This document discusses modal verbs, which are helping verbs that provide information about the main verb. It defines modal verbs like can, could, may, might, should, ought to, had better, must, and have to. It explains the differences between their meanings and uses, such as ability versus permission for can, formal versus informal for could, possibility for may and might, and obligation from feelings versus outside sources for must and have to. The document also compares the meanings and uses of should and ought to as well as had better. Finally, it provides examples to illustrate levels of severity that can be expressed by these modal verbs.

1. Modal Verbs
Helping verbs – they give information about the main verb.
• Necessity
• Possibility
• Permission
• Etc.

2. Modal + Simple Form
 Can: Natalie can play tennis today. (ability or
permission)
 Could: They could play the guitar.
 (Formal of “can”)
 May: It may be a nice day tomorrow.
(possibility)
 Might: It might be a nice day tomorrow.
(possibility)

3.  Should: Natalie should go outside.
 Ought to: You ought to tell her how you
feel!
 Had better: They had better be on time.
 Must: He must eat all his food.
 Have to: I really have to study for my
exam.

4. Must / Have to?
 Similar meaning about obligation
 MUST: Usually used for feelings and
wishes of the speaker.
◦ I must stop smoking. (I want to)
 HAVE TO: Usually obligations that come
from „outside‟
◦ I have to stop smoking (The doctor
ordered me)

5. Should / Ought to?
 They have the same meaning in most
situations (suggestion or
recommendation)
 SHOULD: Suggestion or advice about the
best thing for them.
◦ You should tell her how you feel.
 OUGHT TO: Suggesting something they
can‟t avoid or the last option.
◦ You ought to tell her how you feel.

6. Had better!
 Make suggestions or recommendations
◦ You had better take your umbrella with you
today.
 Warning
◦ You had better be careful with the way you talk
to me in the future!
 Show desperation (hope).
◦ The bus had better arrive on time or I‟ll be late
for work!

7. Levels of severity
 You should clean your room, it is very
messy.
 You ought to clean your room, your
girlfriend is coming to visit you.
 You had better clean your room, or you
will be grounded!