Passages 1 - Unit 2

Mistakes and mysteries

What did I get myself into usually means what kinds of problems am I about to encounter. 

Past modals and phrasal modals of obligation

Some past modals and phrasal modals of obligation are stronger than others.

Strong obligation. To show that there was no choice about doing the action, use was/were to

or had to. Note that must is not used in the past. Instead, use had to.

My parents had to go to school on Saturdays.

Expectation. There was a general expectation that an action was required or prohibited.

She was supposed to talk to my professor after class. (But she probably didn 't.)

He wasn't supposed to drive the car to school. (But he probably did.)

Advisability. There was a good idea or a correct action in a particular situation, but it was

or was not done. He should have taken better notes in class. (But he didn't)

She shouldn't have bought such an expensive jacket. (But she did.)

Modal Verbs of Obligation

Modals with multiple uses

Degrees of certainty range from very certain to uncertain.

Very certain. To show that you think something was probable in the past, use must have,

must not have, can't have, or couldn't have.

Jake had a stomachache last night after dinner. He must have eaten too much.

Sofia was at a movie with me last night. You couldn't have seen her at the mall!

Uncertain. To show that you think something was possible in the past, use could have,

may have, might have, may not have, or might not have.

Jun Ho is usually here by now. He could / may / might have missed the bus this morning.

Tanya was supposed to meet me before school. She may / might not have gotten the message.

modals of lost opportunity

Listen this Podcast 

Past Modals: Should Have, Could Have, Would Have (Review)