In Spanish, the simple present tense (el presente or el presente de indicativo) is used to talk about habitual actions, routines, things happening now or in the near future, universal truths, facts, hypotheticals, lapses of time, and for ordering in restaurants and stores.
On the other hand, the preterite tense (el pretérito) is used to describe actions completed at a point in the past. It is used to talk about beginnings and ends. There are two forms in this verbal tense, namely: Regular Preterite Forms and Irregular Preterite Forms.
So, let's change these sentences from the present tense to the preterite tense:
Q14. Ustedes lavan
In preterite tens: Ustedes lavaron
The verb we use in this sentence is lavar, that is regular. Why does the conjugation is like that? In Spanish, you can recognize only two sets of endings for regular preterite verbs, one for ar verbs and one for both er and ir verbs. If you want to conjugate a regular verb in the preterite tense, you must remove the infinitive ending (ar, er, or ir) and add the preterite ending that matches the subject. Check out the Table below of regular preterite endings.
Q15. Raúl estudia
In preterite tense: Raúl estudió
The verb estudiar is regular. This verb has an ar ending. The noun in this sentence matches the third-person singular (he - él). So, from the figure below the conjugation is estudió.
Take into account that the first person singular (yo), third person singular (él, ella), and second person formal singular (usted), the preterite forms have tildes (that is, written accents) on the final vowel. Consider that one little tilde can change both the tense and subject of a sentence.
Q16. Usted manda
In preterite tense: Usted mandó
The verb mandar is regular. This verb has an ar ending. The noun in this sentence matches the second-person singular (formal you - usted). So, from the figure below the conjugation is mandó
Q17. Ella lava
In preterite tense: Ella lavó
The verb lavar is regular. This verb has an ar ending. The noun in this sentence matches the third-person singular (she - ella). So, from the figure below the conjugation is lavó
Q18. Miguel y Ana llegan
In preterite tense: Miguel y Ana llegaron
The verb llegar is regular. This verb has an ar ending. The noun in this sentence matches the third-person plural (they - ellos). So, from the figure below the conjugation is llegaron
Q19. Los amigos cantan
In preterite tense: Los amigos cantaron
The verb cantar is regular. This verb has an ar ending. The noun in this sentence matches the third-person plural (they - ellos). So, from the figure below the conjugation is cantaron
Q20. Ramón llama
In preterite tense: Ramón llamó
The verb llamar is regular. This verb has an ar ending. The noun in this sentence matches the third-person singular (he - él). So, from the figure below the conjugation is llamó