2. Past modals and phrasal modals
To describe obligations in the past:
should have
was supposed to
had to
needed to
3. In which situations the plants were watered?
I was supposed to water my neighbor’s
plants.
I had to water my neighbor’s plants.
I should have watered my neighbor’s plants.
I needed to water my neighbor’s plants.
I didn’t have to water my neighbor’s plants.
4. I should have stayed home and studied!
It was a good idea, but I didn’t do it.
5. I was supposed to be studying this weekend.
It was required, but I didn’t do it.
6. We had to wear a uniform.
We were forced to do this.
7. I didn’t have to go with my friends, but I did.
There was no obligation.
8. I thought I needed to have more clothes.
I thought it was necessary.
9. Strong obligation
To show that there was no choice
about doing the action. USE:
• was / were to
• had to
My parents had to go to
school on Saturdays.
10. Expectation
There was a general
USE:
expectation that an action • be supposed to
was required or prohibited.
She was supposed to talk to
my professor after class.
He wasn’t supposed to drive
the car to school.
11. Advisability
There was a good idea or a correct action in a
particular situation, but it was or was not done.
USE:
• should (not) have
He should have taken better notes in class.
She shouldn’t have bought such an
expensive jacket.
12. Necessity
The action was considered to be necessary or
unnecessary; however, unlike “had to”, there is
a choice about doing or not doing the action.
I needed to make an USE:
appointment with the • needed to
counselor. • didn’t need to
I didn’t need to buy the text book,
but I thought it looked interesting.
13. No obligation
There is complete choice about
doing the action.
USE:
• didn’t have to
I didn’t have to take piano
lessons, but I wanted to.