Answer:
With a verb that ends with ar, the endings that you switch in depend on the subject.
Yo - o
Tu - as
El , ella , ested - a
Nosotros - amos
Ellos - an
For gustar, it's a bit different. If the subject is singular (one), then write gusta. If it's plural (multiple), write gustan. Also:
Talking about what you (yourself) likes - Me
Talking about what you (person you are talking to) likes - Te
Talking about what he she likes - Le
Talking about what we (yourself and other people) like - Nos
Talking about what they (multiple other people) likes - Les
Hope this helps!
