Answer:
The correct answer in each case is:
<em>1. </em><em>Juan compra helado para mi. Juan </em><em><u>me</u></em><em> compra helado.
</em>
<em>2. </em><em>Mis hermanas y yo </em><em><u>nos</u></em><em> gusta pizza.
</em>
<em>3. </em><em>El hombre </em><em><u>le</u></em><em> gustan papas fritas.
</em>
<em>4. </em><em>Ella da flores a Juan. Ella </em><em><u>le</u></em><em> da flores.
</em>
<em>6. </em><em>A Ana y Sara </em><em><u>les gusta</u></em><em> el libro.
</em>
7. <em> </em><em>A mí </em><em><u>me gustan</u></em><em> las clases de matemáticas.
</em>
8. <em>A los perros </em><em><u>les gusta</u></em><em> comer.
</em>
9. I don’t care.
10. <em><u>Te quedan</u></em><em> tres días.</em> (You have three days left.)
11. <em>Antes de servir la cena, María tiene que </em><em><u>poner la mesa</u></em><em>.
</em>
12. <em>Mi </em><em><u>hermanastro</u></em><em> es el hijo de mi madrastra.
</em>
Explanation:
The translation of the sentences is:
1. Juan buys ice cream for me. Juan buys <u>me</u> ice cream.
2. My sisters and I like pizza.
3. Man likes potato chips.
4. She gives Juan flowers. She gives <u>him</u> flowers.
6. Ana and Sara <u>like</u> the book.
7. <u>I like</u> math classes.
8. Dogs <u>like</u> to eat.
9. <u>I don't care</u>.
10. <u>You have</u> three days left.
11. Before serving dinner, Maria has to <u>set the table</u>.
12. My <u>stepbrother</u> is my stepmother's son.
<u>The object pronouns</u> could be said to be nouns that are located in the complement of a sentence and <u>serve to identify towards whom the action is directed</u>. Since they are linked to personal pronouns, here is the object pronoun that applies to each one in Spanish:
- <em>Yo: </em><u><em>me</em></u><em>.</em>
- <em>Tú: </em><em>te.</em>
- <em>Usted/Él/Ella/Ello: </em><u><em>le</em></u><em>.</em>
- <em>Nosotros/Nosotras: </em><u><em>nos</em></u><em>.</em>
- <em>Ustedes/Ellos/Ellas: </em><u><em>les</em></u><em>.</em>
Knowing this, <u>the only thing left for you is to recognize the noun to which the action is directed, then replace it with its respective personal pronoun and use the object pronoun that applies</u>.