1. MODAL VERBS
MODALS OF OBLIGATION

2. What are MODAL VERBS? HE MUST TOMORROW
They are auxiliary verbs, they go with other verbs

3. What are MODAL VERBS? HE CAN WILL MEET YOU
2 modals verbs cannot go together
HE MUST TO MEET YOU TOMORROW
Followed by infinitive without “to”, except modal verb HAVE TO.

4. What are MODAL VERBS? HE CANS MEET YOU Don’t have 3rd person “-s”
LAST YEAR I CANNED
Don’t have endings like -ed, -ing, etc

5. What are MODAL VERBS? DO CAN YOU MEET ?) I DON’T CAN MEET
Don’t use do/does in questions/ negatives, but use inversion in questions and “NOT” after the modal

6. OTHER TENSES MUST: past & future with HAVE TO
When I was young, we had to wear a uniform at school
Next year you will have to study harder

7. MUST & HAVE TO I must finish my homework before 8
We have to start work at 9 am
They are both used to express that something is necessary

8. MUST
I must find a hotel to stay at tonight (“I have to find a hotel” is also possible)
The speaker decides that something is necessary (INTERNAL decision)

9. HAVE TO I have to wear a uniform
Somebody else has made the decision, it’s not the speaker’s opinion (EXTERNAL decision, RULE)

10. MUSTN’T & DON’T HAVE TO Very different meanings in negative:
You mustn’t open the door
You don’t have to open the door

11. MUSTN’T
You mustn’t open the door. Lately there have been many robberies in the neighbourhood.
(It’s forbidden /prohibited)

12. DON’T HAVE TO You don’t have to open the door. I have the keys.
(It’s not necessary)

13. SHOULD / SHOULDN’T I think you should see the doctor
I think you shouldn’t watch so much TV
Give an opinion about what’s the best thing do do.
Not as strong as MUST /HAVE TO:
You must see the doctor
You have to see the doctor (You have no alternative)