Had beter similiar to should. ( If you don’t do, something bad may be happen.)
Had better (Meaning is presen tor future)
I had better take a taxi or I will be late.
You had better take your rain coat. it might rain.
You look tired. You had better go to bed early.
You look ill. You had better not go to school today.
Are you going to cinema tonight? No I had better not. I have lot of homework to do.
