Present tense. Which is
Yo- replace the ar with o
Tu- replace ar with as
El/Ella- replace ar with a
Nosotros- replace ar with amos
Vosotros- replace ar with áis
Ellos- replace ar with an
When you have a infinitive verb you have to change the last two letters. If you don’t know, yo means I, tu means you, el/Ella means he/she, nosotros means we, vosotros means y’all, and ellos means they.