Question

Como eu sei qua do devo usar o ARE ou IS?​

Answer 1

I am
You are
She is
He is
We are
They are

Answer 2

Explicação:

Com os pronomes he, she, it, usa-se o is. Com you, we, they, usa-se o are.

I am

You are

He is

She is

It is

We are

You are

They are

Também quando o sujeito está no singular usa-se o is.

Mary is beautiful

Mas quando o sujeito está no plural, usa-se o are

The cars are expensive.