1 . A fish swims faster than a duck
=> A duck swims slower than a fish
or A duck doesn't swim as fast as a fish.
2, => We are interested in playing football very much.(interested in=love toV or ving :thích,yêu..)
3, => Lang Lieu was very poor,so he couldn't buy any special food. ( mệnh đề nguyên nhân,)
4, You shouldn't stay up late. ( should=had better)
5, No one in my class is more intelligent than Mary