Archive for June, 2011

Spanish Literacy Strategies for Young Learners

Wednesday, June 29th, 2011


Emergent Literacy is the precursor for the development of conventional literacy. It is the emergent behaviors children attain as they are consistently exposed to multiple authentic and relevant opportunities in conversations, listening and responding to stories, writing and purposeful play.

Literacy is conventional (formal) reading and writing as it is used for means of daily communication. It is language that develops through consistent exposure to various genres of literature which have resounding themes that are authentic and relevant to personal experiences.

This book presents a comprehensive introduction to literacy. It discuses the importance of home language development and how to acquire literacy naturally. It provides an overview of methods and how skills are transferred from one language to another (Spanish to English).

Table of Contents

  • Principles of literacy
  • Foundations for literacy
  • The syllabic structure of Spanish
  • Introducing the syllables
  • Spanish Stories for Early learners
  • Resources

Todo es canción: Antología poética

Wednesday, June 29th, 2011


Canta el agua en la roca,
el pájaro en la rama
y el poema en la página.

Todo es canción (Everything is Song) gathers some of the most recognized poems by Alma Flor Ada. The 142 pages, in a delightful format, have been illustrated by María Jesús Álvarez. In a 7 pages introduction ¿Qué es poesía? the author explains in clear prose the basic elements of Spanish poetry: Poesía en verso y prosa. El verso libre. La rima. La aliteración. El metro. Imágenes y metáforas. La visión poética are some of the themes explored.

The poems have been grouped by thematic interests: Mi cuerpo y yo [My Body and I], Con los que más quiero [With Those I Love], En la escuela [At School], Para reír y jugar [To Laugh and Play], Aires de la ciudad [City Airs], Somos amigos [We Are Friends], ¡Cuántas delicias! [How Many Delicious Treats], Vuelan y nadan, trepan y saltan [They Fly and Swim, Climb and Jump], Hojas, frutas y corolas [Leaves, Fruits and Petals], Sol y espuma [Sun and Foam], Sueños y fantasías [Dreams and Fanatsy], La fuerza de la palabra [Word Power].


What a joy to see my poems collected this way! Poetry has been a very important part of my life. My grandmother, Dolores Salvador, instilled in me the love for poetry since I was very small. She would recite poems and invite me to recite with her. Some of her favorite has been written by my own grandfather, Medardo Lafuente Rubio, other’s by José Martí. She created her own music for some of Martí’s poems leaving with me the legacy of the particular enjoyment poetry, whether recited or sung, will always bring me. How I hope the children who have access to this book will enjoy the poems it contains and someday discover that they can also write their own poems.

Book Reviews

Criticas. School Library Journal

Ada has edited a number of lovely books of traditional rhymes, but Todo es canción (Everything Is Song) gives her a chance to showcase her own poetry. The selections are organized by theme. “For Laughing and Playing” includes traditional rhymes, with tales of cats and mice and hens. “In School” includes counting rhymes, and “My Books” is a gift for librarians everywhere to share with children. There are selections that will encourage movement, and those that can be adapted as fingerplays. “Sun and Foam,” “Dreams and Fantasies,” and “The Power of Words” all contain thoughtful and powerful pieces. The whole is summed up in the final poem, in which Ada celebrates the song in everything around us, and ends by saying, essentially, “Because you have been born, life wants to sing.” This book is to Latino children what Robert Louis Stevenson’s A Child’s Garden of Verses is to English-speaking youngsters. It is not just a poetry anthology, but truly a lasting contribution to Latino literature that belongs in every library that serves young Spanish-speakers and their parents.
–Tim Wadham, St. Louis County Library, MO


Dancing Home

Wednesday, June 29th, 2011

Watch Video: Alma Flor Ada and Gabriel Zubizarreta dis­cuss their inspi­ra­tion for writ­ing Danc­ing Home.

Book Reviews

San José Public Library

In alternating chapters, the authors tell the story of two cousins Margarita, known as Margie to her school friends, and Lupe. The two girls are the same age, Lupe was born and raised in Mexico, until Margie’s parents arranged for her to come to live with them and go to school with Margie. Margie’s grandparents were all from Mexico, but she was very proud to have been born in Texas. She considered herself to be a true American… Read more »

School Library Journal

Gr 3-6–Margie is proud to be an American, born in the United States. Her parents were born in Mexico and so was her cousin, Lupe, who has come to stay with Margie’s family in California. At first Margie is excited, but that enthusiasm dissipates when Lupe is placed in her classroom. She doesn’t speak English, and Margie’s teacher expects her to translate for her. A couple of classroom bullies seem bent on belittling the cousins’ heritage. Margie is relieved when Lupe is transferred to a bilingual class, leaving a desk near her for the newest classmate, Camille. The girls become great friends. When they’re given a journal assignment, Camille models what it’s like to have a passion as she thinks, researches, and writes about dolphins. Lupe stays after school to learn folkloric dances, and the book concludes with a performance that helps Margie understand how American she is and how her Mexican heritage fits into her identity. This story will assist readers in embracing their own heritage and developing an appreciation for their classmates’ backgrounds. It’s an enjoyable offering (and a great read-aloud) that will capture readers’ attention and have them rooting for the cousins and their friendships and family relationships. A Spanish-language edition, Nacer Bailando, is available simultaneously.
–Helen Foster James, University of California at San Diego


Ten-year-old Margie has spent her entire life trying to fit in—to pass as an American—despite the fact that her parents were born in Mexico. Then, her Mexican cousin Lupe comes to live with them, and her plan goes awry. At first, she resents Lupe for her foreign ways and for monopolizing her parents’ attention; later, she comes to love Lupe as a sister and appreciate the Mexican part of her heritage. Margie begins to master Spanish, enjoys celebrating Navidad, and participates in a Cinco de Mayo folklorico dance at school. Ada, the author of many multicultural titles, including Tales Our Abuelitas Told: A Hispanic Folktale Collection (2006), and Zubizarreta write knowingly of the difficulties of a life lived in two cultures. A subplot involving Lupe’s father (who came to America illegally and later abandoned his family) is also well handled, as is the inclusion of a Ruben Dario poem, “To Margarita.” Give this to fans of Pam Muñoz Ryan’s Esperanza Rising (2000) and Becoming Naomi Leon (2004).

Kirkus Review

Two cousins, one born in Texas and the other in Mexico, learn the importance of family and friendship. As an only child living in California with her Mexican-American parents, Margie Ceballos-González is proud to be American. Everything changes when her cousin Lupe González leaves her mother, stepfather and half-brothers in Mexico to live with Margie and her parents. Years before, Lupe’s father had moved to the United States for work and then disappeared. Margie and Lupe are both in fifth grade at the same school, and Lupe’s presence immediately draws exactly the sort of attention Margie has been trying to avoid. At home, she finds herself competing for attention as her parents welcome Lupe with Mexican foods and Spanish conversation. Sensing her cousin’s dilemma, Lupe finds ways to help Margie appreciate their shared Mexican heritage. Margie thaws, even realizing the beauty of her name, Margarita, which came from one of her mother’s favorite flowers, the daisy. The third-person narration shifts its focus gently from girl to girl, allowing readers access to their thoughts and feelings. The authors also connect Nicaraguan poet Rubén Darío’s “A Margarita” to the story, and the full poem follows the novel in both Spanish and English.

Although sometimes wise beyond their years, Margie and Lupe will charm readers as each girl struggles for belonging and acceptance in this realistic novel. (Fiction. 8-12)

Buy it from your favorite bookstore, order it from Amazon, or get personalized service from DelSolBooks by emailing Ray at

Library Media Connection

When Margie’s Mexican cousin Lupe comes to live with her family, Margie’s carefully constructed American image is at stake. It’s even worse at home where Margie’s immigrant parents begin speaking more Spanish and forming a special bond with Lupe. But over the school year, Lupe and Margie begin to understand the challenges each cousin endures as well as the beauty of their dual cultures. The book reflects this dichotomy by using both Spanish and English, discussing holidays celebrated in Mexico, and celebrating the arts of Spanish-speaking countries. A poem by Nicaraguan poet Rubén Darío holds special meaning for the girls and is included in both languages. While the deliberate moral messages of acceptance and individuality are expressed didactically, Ada and Zubizarreta tackle important topics including immigration, bilingual education, and bullying. This book will speak intimately to readers straddling different cultures and grappling with what it means to be an American. –Kasey Garrison, Library Science Doctoral Student, Old Dominion University, Norfolk, Virginia

From blog Real Discover Grow

Explorations of identity always captures my attention. I first noticed this in college, and since then I have realized that regardless of the target audience, I am always fascinated by the journey. Naturally, when I first heard about Alma Flor Ada and Gabriel M. Zubizarreta’s middle grades novel Dancing Home, I knew that eventually I would just have to read it.

Alma Flor Ada is well-known and respected as an author and educator, and she co-wrote this book with her son. In the book Margie’s life is in flux. Her cousin from Mexico has just come to stay with her family, prompting boys in her school to once again tease her about her full name, saying, “Maaaargaaaareeetaaaa,” multiple times. As a result Margie decides tries to avoid being seen with her cousin. However, her presence makes it hard to continue ignoring her Mexican roots that she has worked so hard to deny, and she starts to wonder what it really means to be American and if it is possible to honor both “her” culture and her parents’.

As Margie is questioning the book shares plenty of insights into her inquiry and realizations as the novel progresses. Parallel to Margie’s story, we also learn about her cousin Lupe and her own struggles dealing with her father’s abandonment and the shifts in her own family dynamics back in Mexico, as well as finding her place in a new country.

The novel is told in third person but mostly sticks to the girls’ thoughts and plot lines. As can be expected, both girls gain a better sense of understanding as the novel progresses, allowing for a nice discussion starter or individual dialogue related to empathy. The book also sprinkles in Spanish phrases here and there, something that I always love. It also incorporates a class writing assignment, prompting inquiry, as well as a natural inclusion of a famous Rubén Darío poem, A Margarita with an English translation, followed by a translation background note at the end of the book. For my dual immersion students, I like that the translation note can prompt thought about what is really important when it comes to translation – literal word for word or capturing the essence.

For the last three years, I have read Cuando Tía Lola vino de visita (a quedarse) (the Spanish translation of Julia Alvarez’s How Tía Lola Came to (Visit) Stay). In Dancing Home, Margie briefly mentions reading the book and making a connection to her life. Just as I was thinking it was a perfect connection as Miguel is also sifting through identity related thoughts thinking about his Dominican relatives and is also originally embarrassed about his aunt who comes to visit from the islands, I was surprised to realize that link was not made. Rather, Margie thinks about the divorce connection when trying to understand how Lupe must feel. Nonetheless, the additional clear links are present, and these two texts would be excellent to pair together. I think that it would be beneficial to have Dancing Home as a read aloud either before or after Alvarez’s book, providing excellent opportunities to see how different characters navigate their feelings related to identity.

So many possibilities for this novel as an educator and a parent… Posted by A. Villagómez

From King County Library System

In Dancing Home by Alma Flor Ada, young Margie (short for Margarita) has worked very hard and long to ensure that her classmates accept her for who she is, 100% American, born in Texas, nothing to do with Mexico or crossing the border or speaking Spanish. Along comes Lupe, Margie’s cousin from Mexico dressed like a fancy shiny doll and speaking no English. Margie tries to stay as far away from Lupe as possible, but all Margie’s efforts to avoid Lupe are squashed when Margie’s teacher assigns Margie the task of translating for and assisting Lupe in the classroom. As if it weren’t bad enough that Margie and Lupe have to be linked in the classroom, Lupe will also be staying with Margie and her parents in their home and Margie’s parents just love Lupe and how she reminds them of their Mexican heritage.

As Margie works to resist the Mexicanness enveloping her, she also begins to uncover the truth about the difficult road her cousin has travelled in order to be where she is today. Suddenly Margie doesn’t mind helping Lupe adjust to life in Texas as she herself learns that speaking Spanish and wearing fancy organza dresses and dancing baile foklórico aren’t so bad after all, when they are done with those you love. Alma Flor Ada is a Cuban American award winning author. As in Dancing Home, Ada’s books for children often address familiar themes of growing up bilingual and bicultural and the experience of being an immigrant.
Posted by Jessica @ Auburn on August 8, 2012 @ 01:49 PM

Kristi Bernard in GoodReads

Margie has been making every effort to embrace her now American heritage. When her cousin Lupe comes to live with them from Mexico, Margie finds that she is having to help Lupe adapt. It isn’t easy since Lupe doesn’t speak English very well and is having trouble keeping up. Margie is having to back track to the Mexican heritage she has been running away from. As Margie lends herself to family traditions and getting acquainted with Lupe, by sharing American experiences and embracing her culture through the eyes of Lupe she begins to better understand her heritage and its importance.

Ada and Zubizarreta have done an excellent job of presenting the Mexican culture through the eyes of a child. The emotions felt through Margie and Lupe will keep young readers turning the pages to see how these two girls cope with change and the challenges it brings. Young readers will learn Spanish terms and their meaning. Parents, teachers and homeschoolers will love sharing this wonderful culture and the true meaning of family and tradition. – Kristi Bernard

English Reading Group Guide

Discussion Questions

1. As Margie visits the principal’s office in preparation for Lupe’s enrollment in her school, she notices a map of North America with vivid and bold colors for the United States and Canada, yet the part of Mexico included is displayed in a drab, sandlike color. In what ways does the imagery of the map capture Margie’s feelings for her parents’ birthplace? What is it about her understanding of Mexico that makes her feel this way?

2. Consider the dress that Lupe wears on the first day of school. What does it symbolize for Lupe? Why does Margie have such a different reaction to it? Why are Margie’s feelings so strong? How do you think you would have felt in Margie’s place?

3. Though she is initially hesitant, why does Lupe ultimately choose to go to California with her aunt Consuelo? Lupe “feels like a stranger in her own home”—how is that so? What changes in her home life have promoted this shift?

4. Margie really prides herself with being born north of the border as an American. In your opinion, what leads Margie to have such strong feelings toward her citizenship? How do you feel about her attitude regarding her place as a US citizen? Do you think the place of birth is the only qualification to be a good citizen? Why or why not?

5. After working hard to convince her mom that rather than long, straight hair, a head full of brown curls is the ideal image of a true American girl, Margie feels jealous of her mother’s intimacy with Lupe as she assists her niece with brushing and braiding her hair. In your opinion, do you think Margie has a reason to be jealous? Why or why not?

6. Explain the significance of the title, Dancing Home. What events and relationships portrayed in the book are expressed by this title?

7. While discussing her unwillingness to speak Spanish in the classroom to assist her cousin Lupe, Margie tells her mother, “But we live in America, Mom. This is an English-speaking country. Live in America, speak American. That’s what they all say.” Have you heard similar statements before? Do you speak a language other than English? Does anyone in your family? What are your feelings about being bilingual?

8. How does Margie’s interpretation of her peers’ attitudes toward Mexico impact her relationship with her parents, and with Lupe?

9. Why does Margie feel so disappointed that with Lupe’s arrival, the way Margie’s family has celebrated Christmas in the past is put aside to celebrate a more traditional Mexican Christmas? Do you think her parents are right to do so? What do Margie and Lupe gain from this holiday experience?

10. Consider the variety of settings for Dancing Home and name the three places you believe to be most important to the story. Using textual evidence from the book, explain why you find them to be significant to the story.

11. For what reasons do you think Margie feels connected to her friend Camille? In what ways are the two of them similar? How would you characterize the relationship between the two of them, and how does it change over the course of the novel?

12. Describe Lupe. How does she change throughout the story? Have you ever shared any of her feelings? Explain.

13. In what ways does the visit by her uncle Francisco help make Margie more understanding of the struggles faced by Lupe? Francisco failed Lupe in many ways, yet he is finally able to give her a powerful gift. Do you believe Lupe will benefit from her father’s message? Explain your answer.

14. Consider the novel’s cover art. In what ways is the image represented symbolic for the events that transpire throughout the course of the book?

15. In your opinion, in what ways does Margie’s shift in understanding of who she is change throughout the course of the novel? In what ways does Camille help Margie better understand and appreciate her heritage?

16. Do you feel that reading this book has given you new insight about what immigrant students may experience? About any other issue? Please explain your answer.

17. Using the phrase, “This is a story about . . .” supply five words to describe Dancing Home. Explain your choices.

Activities and Research

1. In the course of the novel, readers learn that Margie’s grandfather was part of the Bracero Program. Using the library and the internet, research to learn more about this government program, being sure to consider how many workers participated, where these farm workers provided assistance, and what the benefits and challenges were.

2. In Dancing Home, Margie struggles when her American Christmas is modified so that her family can celebrate a more traditional Mexican holiday. Using the library and the internet, research what the major similarities and differences are between Christmas in Mexico and Christmas in the United States.

3. Make thematic connections. Consider the themes of Dancing Home: examples include (but are not limited to) family, friendship, sacrifice, and courage. Select a theme and find examples from the book that help support this theme. Create a sample Life Lesson Chart using the model at:

4. Dancing plays an important role throughout the novel and in particular, in Margie’s relationship with her cousin Lupe. Find out more about folklorico dances, being sure to focus on the importance of music, costumes, and their purpose for celebrations like Cinco de Mayo.

5. Language is also a very important theme in Dancing Home. Find out about the language history in the United States. Which languages were spoken in this land before English? What are the personal benefits of speaking more than one language? What are the benefits for society when languages are maintained?

6. In Dancing Home, part of Margie’s and Lupe’s stories focus on their connection and relationship with each other and their need to come together as a family. Consider your most special relationships. What makes these individuals so important? Compose a personal journal entry where you share your thoughts, and be sure to answer the following questions:

  • Who are the individuals who mean the most to you?
  • Why are these particular relationships so special?
  • What’s the greatest sacrifice you’ve made for the people you love?
  • In what ways have the changes you’ve experienced in your life affected those to whom you are closest?

Share your writing with the group.

Guide written by Rose Brock, a teacher, school librarian, and doctoral candidate at Texas Woman’s University, specializing in children’s and young adult literature.

This guide has been provided by Simon & Schuster for classroom, library, and reading group use. It may be reproduced in its entirety or excerpted for these purposes.

Spanish Group Reading Guide

Preguntas para el diálogo

1. Cuando Lupe empieza a asistir a su escuela, Margie va a hablar con la directora. Mientras espera observa un mapa de la América del Norte. Los Estados Unidos y Canadá aparecen en colores vivos, mientras que el trozo de México que el mapa incluye es de un color de arena sin mucha vida. ¿Refleja este mapa los sentimientos de Margie hacia la patria de sus padres? ¿Por qué? ¿Qué piensa ella sobre México que la hace sentirse así?

2. ¿Qué significa para Lupe el vestido que usa el primer día de clases? ¿Por qué reacciona Margie de un modo tan diferente sobre el vestido de Lupe? ¿Por qué son sus sentimientos tan fuertes? ¿Cómo te hubieras sentido tú en el lugar de Margie?

3. Aunque al principio siente muchas dudas, ¿por qué acepta Lupe ir a California con su tía Consuelo? ¿Cuáles son las causas para que Lupe “se sienta en su propia casa como una extraña”?

4. Margie se siente muy orgullosa de haber nacido al borde de la frontera y de ser por eso estadounidense. En tu opinión ¿por qué es tan importante para Margie saber que es ciudadana de los Estados Unidos? ¿Qué piensas sobre su actitud con respecto a su ciudadanía? ¿Crees que el lugar de nacimiento es lo único importante para ser un buen ciudadano? ¿Por qué piensas así?

5. Margie ha luchado por convencer a su madre que en lugar del pelo largo y lacio, una cabeza rizada es la imagen ideal de una niña estadounidense. Pero luego, al ver a su madre cepillarle y trenzarle el pelo a su prima, siente celos de la cercanía entre su madre y Lupe. ¿Crees que los celos de Margie están justificados? ¿Por qué?

6. Explica el significado del título Nacer bailando. ¿Qué situaciones y relaciones presentadas en el libro están expresadas en este título?

7. La maestro le ha pedido a Margie que le traduzca a Lupe en la clase. Cuando Margie conversa con su madre sobre su imposibilidad de traducir, Margie afirma: “ —Pero vivimos en los Estados Unidos, mami. En este país se habla inglés. «Si vives aquí, habla inglés» es lo que dicen todos.” ¿Has oído tú a alguien decir algo así? ¿Hablas tú algún otro idioma además del español? ¿Alguien en tu familia habla otro idioma?¿Qué sientes sobre ser bilingüe?

8. ¿Qué efecto tienen las actitudes de sus compañeros sobre México en las relaciones de Margie con sus padres y con Lupe?

9. ¿Por qué se siente Margie tan desilusionada de que a causa de la presencia de Lupe su familia deje de celebrar las Navidades como lo ha venido haciendo y la celebración tome un carácter más mexicano? ¿Crees que sus padres han actuado bien? ¿Qué ganan Margie y Lupe de esta experiencia?

10. Considera los distintos lugares que aparecen en Nacer bailando y nombre los tres que te parecen más importantes para el relato. Utilizando las palabras del libro, explica por qué te parecen importantes para la narración.

11. ¿Por qué razones se siente Margie cercana a su amiga Camille? ¿En qué se parecen? ¿Cómo describirías su amistad y cómo cambia a través de la novela?

12. Describe a Lupe. Explica los cambios que experimenta a través del relato. ¿Has sentido tú alguna vez sentimientos similares a los suyos? Explica cuándo y por qué.

13. ¿Cómo contribuye la visita de su tío Francisco a que Margie entienda mejor las dificultades por las que Lupe ha pasado? Francisco le ha fallado a Lupe de distintas maneras, pero al fin le da un regalo importante. ¿Crees que Lupe se beneficiará del mensaje de su padre? Explica tu respuesta.

14. Observa la ilustración de la cubierta del libro. ¿Cómo representa la imagen simbólicamente lo que ocurrirá en la novela?

15. En tu opinión, ¿cómo cambia a través de la novela el concepto que tiene Margie de sí misma? ¿Cómo ayuda Camille a Margie a comprender y apreciar su herencia cultural?

16. ¿Sientes que leer este libro te ha hecho comprender mejor la experiencia de los estudiantes inmigrantes? ¿Otros temas? Por favor, explica tu respuesta.

17. Completa la oración “Esta novela trata de…” utilizando cinco palabras que describan Nacer bailando. Explica por qué elegiste cada palabra.

Actividades e investigación

1. En la novela se menciona que el abuelo de Margie participó en el Programa de Braceros. Utilizando la biblioteca y el internet busca información sobre este programa federal. Averigua cuántos trabajadores participaron, en qué lugares trabajaron estos campesino migrantes, cuáles fueron los beneficios que proporcionaron y las dificultades que encontraron.

2. En Nacer bailando, a Margie se le hace difícil cuando su familia cambia el modo de celebrar las Navidades y la convierte en una celebración mexicana. Utilizando la biblioteca y el internet investiga cuáles son las semejanzas y diferencias entre los modos de celebrar las Navidades en distintas partes de México y en los Estados Unidos.

3. Establece conexiones temáticas. Considera los temas de Nacer bailando. Algunos ejemplos son familia, amistad, sacrificio, valentía, idioma y cultura, aunque los temas no se limitan solo a estos. Selecciona un ejemplo en el libro que te permita desarrollar este tema siguiendo este esquema:
TEMA Indica el tema
EVIDENCIA Indica cómo aparece en el libro
SIGNIFICADO PERSONAL ¿Qué significa este tema para mí? ¿Cómo se relaciona con mi vida?

4. El baile juega un papel importante en esta novela especialmente en la relación entre Margie y su prima Lupe. Busca información sobre los bailes folklóricos mexicanos, que destaque la importancia de la música, los trajes, y su papel en todo tipo de celebraciones, que incluyen pero no se limitan al Cinco de Mayo.

5. El lenguaje es un tema importante en Nacer bailando. Investiga sobre la historia del lenguaje en los Estados Unidos. ¿Qué idiomas se hablaban en el territorio que es hoy los Estados Unidos antes que el inglés? ¿Cuáles son los beneficios personales de hablar más de un idioma? ¿Cuáles son los beneficios para la sociedad cuando los idiomas que hablan sus habitantes se mantienen?

6. En Nacer bailando, parte de la historia se centra en la relación entre Margie y Lupe y las de ambas con sus familiares. Piensa en las personas que son más importantes en tu vida. ¿Por qué son importantes para ti? Comparte tus sentimientos en tu diario personal. Asegúrate de contestar estas preguntas:

  • ¿Quiénes son las personas más importantes para ti?
  • ¿Por qué es tu relación con estas personas especial?
  • ¿Cuál es el mayor sacrificio que has hecho por alguna persona a la que quieres?
  • ¿Ha afectado algún cambio en tu vida a las personas cercanas a ti? ¿Cómo?

Comparte con el grupo lo que has escrito.

Guía escrita por Rose Brock

Simon & Schuster provee esta guía para su uso en aulas, bibliotecas y grupos de lectura. Puede ser reproducida en todo, o en parte, para esos usos.