Explanation:
* the numbers inside the [] are the exercice I'm using to exemplify the explanation
*there might be other rules o exeptions, this are some things I've noticed being a native speaker
when refering to someone in specific (using pronouns ella, él or usted) the verb ends in "-ió" [2, 3, 8, 9]
if you talk about you and another person (nosotros) the verb ends in "-imos" [1, 7, 10]
if you talk about you, the verb ends in the last i and you put the "tilde" on it, so "-Í". if the verb does not have an i by the end, you delete the last syllable and put one. [5]
if you talk about a group of people you are not including yourself (ellos, ellas, ustedes) the verb ends in "-eron" [4, 6]
Answers:
2. Usted consiguió dinero
3. Claudia sirvió la cena
4. Nuestros amigos pidieron mucha comida
5. Preferí comer poca comida
6. Ustedes se sintieron mal
7. María y yo repetimos nuestros discos
8. Javier prefirió escuchar
9. Marta durmió durante la fiesta
10. Nosotros nos divertimos mucho
