Questions & Answers about Quiero ir a la biblioteca mañana.
In Spanish, the verb ending already tells you who the subject is, so subject pronouns (like yo) are often dropped.
Quiero can only mean I want, so yo is not required.
You can say Yo quiero ir a la biblioteca mañana if you want to emphasize I (for example: Yo quiero ir, pero él no quiere – I want to go, but he doesn’t).
Without special emphasis, the more natural version is simply Quiero ir a la biblioteca mañana.
Quiero is the first person singular (yo) of querer in the present indicative.
- Infinitive: querer – to want / to love
- Present tense (singular):
- (yo) quiero – I want
- (tú) quieres – you want (informal, singular)
- (él / ella / usted) quiere – he / she wants, you want (formal, singular)
So Quiero ir… literally means I want to go… right now or in general (with mañana specifying the future time).