Why would you use tú when speaking to a classmate?

Tu is informal

Explanation:

you would use usted if talk to someone you barely know but a classmate you would use tu because it is less formal

hi, so i look up the video and the 2 poems are the same

en la oscuridad te llame.

de la oscuridad me llamaste.

reconoci tu voz.

reconosiste la mia.

vente para aca, dije.

respondiste: donde estas papa ? no te veo.

aqui, estoy aqui, dije.

tengo mido, dijiste.

no, mi hijo esperate! vengo a donde estas.

esta oscuro, no veo nada, tengo miedo.

no tengas miedo hijito, ahorita vengo

pronto papa, te espero.

this question is given using the conditional form. conditional tenses are is used when talking about hypothetical situations and probabilities. also, this is used when making polite requests. so comprarías is the conjugation of the verb comprar that matches the second person singular in the conditional. finally:

¿cuál comprarías tú?