1. Right answer:
está
Está is the conjugation of the verb estar for the third person singular in the simple present. The simple present tense is used to talk about habitual actions or routines. On the other hand, we use the verb estar is being used here to indicate an ongoing action, that is, Armando spends all day in the swimming pool. Thus:
Armando está en la piscina todo el día
2. Right answer:
puse
Puse is the conjugation of the verb poner for the first person singular in the preterite tense. This tense is one of two simple past tenses. It is used to describe actions that took place or were completed at a certain point in the past. So, the action to put the envelope in the mailbox took place at a certain point in the past. Therefore, the sentence is:
Yo puse el sobre en el buzón
3. Right answer:
mandaste
We can use several ways to indicate that a person sent a postcard. So we can use the verb mandar or enviar. Both verbs mean the same word in English to send. Thus, mandaste is the conjugation of the verb mandar for the second person singular in the preterite tense. Other way to say this is by using the conjugation enviaste of the verb enviar. Finally, the sentence is:
Tú mandaste la tarjeta postal a tu familia
4. Right answer:
pusieron
Pusieron is the conjugation of the verb poner for the third person plural in the preterite tense. So los viajeros can be replaced by ellos that is the subject pronoun for the third person plural. Here the action is to put the clothes in the suitcase. Finally, the sentence is:
Los viajeros pusieron la ropa en la maleta
5. Right answer:
estampilla
Basically, estampilla and sello means the same word in English stamp. The only difference is that estamplilla is a feminine noun and sello is a masculine one. Since the word before the blank is the indefinite article una that is feminine and singular, the noun that matches this article must be feminine and singular as well. That's the reason why we choose estampilla over sello.
Yo pongo una estamplilla en el sobre
