What are the modal verbs of duty and advice?
Should/shouldn't, ought to/oughtn't to
I ... leave soon, it's getting late. (obligation and necessity)
must
You really... to be an expert to make such a statement. (duty and advice)
ought
What are the modals of prohibition?
Can't, couldn't, mustn't
At my previous job we ... make personal calls during worktime. (prohibition)
were forbidden/ weren't allowed/ couldn't
Name the modal verbs of ability.
Can, could, be able to.
Which modal verb is used to indicate an obligation coming from someone else?
Have to
It was a long and exhausting trip but I ... to enjoy the drive.
managed
What are related verbs used for permission?
Be allowed to/be permitted to
She ... cook better than anyone I know! (ability)
can
What is the difference between can and might?
...
You ... worry to much. Take a deep breath, think and make a plan. (no obligation)
needn't
There ... be life on other planets. (pissibility)
could/might
Required to & obliged to are used for...
Obligation & necessity