English Modal Verbs: Verbs of Deduction, Expectation, and Preference in English

Modal verbs are special verbs in the English language. You may already know that they can express ability, permission, possibility, obligation, or give advice. In this posting I talk about different uses for the modal verbs you may already know. I show you haw to use these verbs to express deductions (conclusions), expectations, and preferences. I will include many example sentences. The download at the end will give you additional practice using these verbs.

Let us look at how these special modal verbs are used.

Here is the lesson I taught on modal verbs of deduction in English

You may already know the modal verbs must, have to, can, could,should, might, and may. These verbs can also be used as verbs of deduction. Deduction means that you have looked at the facts and deduced (figured it out) and come to a conclusion. Let’s look at how these words can be used. Use this formula: subject + modal + base form of the verb.

Modal Verbs of 100% certainty

Use these modal verbs when you are 100% certain that something is happening or will happen.

1. must–He must be at the hotel by now. His plane landed four hours ago.    Note that this is not about an obligation. You know that his plane landed four hours ago. That’s a long time, and perhaps his hotel is only 30 minutes away from the airport. You have figured it out.
2. have to–He has to be in Colorado Springs by now. It takes an hour to drive there, and he left three hours ago.    See note above.

The negative for must or have to is can’t or couldn’t.

1. He can’t be at the hotel yet. His plane just landed 10 minutes ago.    This is not about ability. This is a conclusion that you figured out.
2. He couldn’t be in Colorado Springs yet. It takes an hour to drive there, and he only left 15 minutes ago.   This is not about past ability. Again, this is a conclusion that you have figured out.

Modal verbs of 80% certainty

Use these modal verbs when you are mostly certain (80%) that something is happening or will happen.

1. should–He should be at the hotel by now. His plane landed two hours ago.   You are not giving him advice. You are mostly sure than his plane landed on time, and the hotel is 30 minutes away form the airport. So unless there is a delay, you have figured out that he is likely to be at the hotel.
2. shouldn’t–He shouldn’t be at the hotel yet. His plane only landed 45 minutes ago.   See note above.

Modal verbs of 50% certainly

Use these modal verbs when you are not completely sure that something is happening or will happen.

1. may–He may be at the hotel by now, if his plane wasn’t late.   There is a string possibility that his plane is late, so there is  A 50/50 chance that he is at the hotel now.
2. might–He might be in Colorado Springs by now, but there is a lot of traffic on the road.   See note above.
3. could–He could go out to dinner tonight if he has enough money left after paying his bills.   See note above.

The negative of these modal verbs are may not, might not, and couldn’t.

Modal verbs of expectation

Use the following formula when something to happen: subject + modal + base form of the verb. The following are modal verbs of expectation.

1. should–She should be on her way to work now. She is never late.   You know that she is never late. You also know that it is almost time for work, so you expect her to be in her car driving.
2. ought to–The package I sent ought to be there by now. I sent it two weeks ago.  You know that it only takes one week for a package to arrive, so you are expecting it to be there by now.
3. supposed to be–Use this formula: subject + am/are/is + supposed to be. He is supposed to be here at 2:00 pm. It’s now 3:00 pm, so he must be here by now.    You expect that he arrived an our ago.

Modal verbs of preference

Modal verbs of preference express something that you want or prefer. Use these verbs: prefer, would prefer, or would rather.

Modal verbs of preference to make an affirmative statement with prefer of would prefer

Use this formula to use modal verbs to make an affirmative statement:  subject + prefer/would prefer + ing form of the verb

I prefer driving myself. 

She would (She’d prefer) prefer going by herself. 

Modal verbs of preference to make an affirmative statement using would rather

Use this formula with modal verbs of preference to make an affirmative statement with would rather: subject + would rather + base form of the verb

I would rather drive myself. 

Making a negative statement with the modal verbs using would rather

Use this formula to make a negative statement with the modal verb would rather: subject + would rather + not + base form of the verb.

I would rather not drive tonight. 

Negative statements with the modal verbs prefer and would prefer

Here is the formula when you have a negative statement and you wish to use the modal verbs prefer or would prefer: subject + prefer not/would prefer not + to + base form of the verb

She prefers not to drive tonight. 

We would prefer not to have hamburgers again for dinner. 

Using modal verbs of preference when you have two distinct choices

Use this formula to express a preference with modal verbs: subject + would rather + base form of the verb + than + base form of the verb or subject + would prefer + to base form of the verb + than + (to) base form of the verb

I  would rather fly than drive to California. 

I would prefer to eat at a nice restaurant than  (to) eat at McDonald’s. 

Using modal verbs of preference when you want someone to do something

Use this formula with modal verbs of preference when you want someone to do something: subject + would rather/would prefer + (that) + subject + simple present or simple past

I would rather (I’d rather) you work tonight instead of tomorrow. 

I would prefer (I’d prefer) that you worked tonight instead of tomorrow. 

Answering a question using modal verbs of preference

Here is how to answer a question using modal verbs of preference.

Would you like to have a drink with me? sure, I’d love to.  No thanks, I’d rather not.

You now know some additional uses for some modal verbs you may have already known. If you have deducted or figured out something use the verbs must,have to, should, may, might, or could. To talk about something you expect to happen, use should, ought to, or supposed to be. When you express your preferences, use prefer, would prefer, would rather, or would rather not. The download will give you additional practice using all of these modal verbs.

You can download the practice sheet now!

Idioms of the day

1. sticky fingers–This means that someone  has a tendency to steal. Maria was shocked to discover that her new friend had sticky fingers and stole things from her house. 
2. to pull someone’s leg–This means to tease or trick someone. He told me that he won the lottery, but I don’t believe him. I think he’s pulling my leg.