The last choice should be the correct answer.
19- A está basically mean it is estoy means i am and sense the question isn’t in first person it can be estoy that would mean juan is talking abt himself
20- B ^
21- B ^
Conocía, trust me, I speak spanish.
Answer:
Elena y yo fuimos al partido de futbol. (Preterite tense form)
Elena y yo íbamos al partido de futbol. (Imperfect form)
Elena y yo vamos al partido de futbol. (Present form)
Elena y yo iremos al partido de futbol. (Future form)
Explanation: