Ariana and Billie is singers
Ariana and Billie ARE singers
They is a group
They ARE a group
Millie am famous
Millie IS famous
We am learning English
We ARE learning English
They is amazing actors
They ARE amazing actors
She am a very good singer
She IS a very good singer
You is happy
You ARE happy
I is a student
I AM a student
She are Mexican
She IS MEXICAN