Third Meeting Review

There is no polite request in the past

There is only have to not has to


Certainty
He may have be sick --> now
He may have been sick --> past

How to differentiate advice and certainty is from the context.

Advice: You should study harder (now)
You should have come earlier (past)

Certainty: You should have work harder
You should have kept your promise



Had better (advice in present)

I had better go to school (OK)
I had better to go to school (X)
I had better went to school (X)