To be
He doesn't walk to work every day.
Right
Luz and Mateo doesn't know the answer.
Luz and Mateo don't know the answer.
Julian and Marcos am brothers.
Julian and Marcos are brothers.
He doesn't watches TV
WRONG. He doesn't watch tv
We lives from Brazil.
WRONG We are from Brazil / We live in Brazil.
Am we in this group?
Are we in this group?
You and me speaks Chinese.
You and me speak Chinese.
I doesn't play videogames
WRONG. I don't play videogames