Can I know what is grammatically wrong with these sentences..(i) Let us enjoy. (ii) Two and two makes four. (iii) If i were him, I would help you.

Can I know what is grammatically wrong with these sentences..(i) Let u

1.	Can I know what is grammatically wrong with these sentences..(i) Let us enjoy. (ii) Two and two makes four. (iii) If i were him, I would help you.
Answer» III) If I was him,I WOULD HELP you. No. iii) was WRONG.