The Grammaring Guide to English Grammar with Exercises

Modals to express criticism: CAN, COULD, MIGHT, SHOULD

Present and future

Can, could, might and should/shouldn't + infinitive are used to express criticism or disapproval with reference to present or future time:

You

can be

really annoying, you know!

You

shouldn't be sitting

here just doing nothing!

You

might be

more polite.

George

could

really

help

you!

Past

Could, might and should/shouldn't + perfect infinitive are used to express criticism or disapproval with reference to past time:

I

should have booked

a table in advance.

Of course, you feel sick. You

shouldn't have eaten

so much chocolate.

You

might have told

me you weren't coming!

George

could

really

have helped

you!

Quotes:

No city should be too large for a man to walk out of in a morning. - Cyril Connolly