1. Helen and me are good friends.
WE are good friends.
2. Nick is from Great Britain.
HE is from Great Britain.
3. Are you and your sister twins?
Are YOU twins?
4. The cat is drinking milk.
IT is drinking milk.
5. Iren is a student.
SHE is a student.
6. Bert and his brother live in London.
THEY live in London.