Today we’re going to discuss some more ways that modals can be used in English. A modal is a special type of auxiliary verb that is used to express a speaker’s attitudes and the strength of those attitudes. This lesson will explain how English uses modals to express necessity, advisability, intentions, and suggestions.
Using Modals to Express Necessity
Must and have to are both used to express necessity in English. Have to is used more often in everyday conversation, while must usually conveys a greater sense of urgency:
I have to speak with John when he returns home.
I must speak with John as soon as possible.
Have got to is a less formal version of have to that is acceptable for casual speech. Native English speakers frequently shorten this to the grammatically incorrect I’ve gotta:
I have got to speak with John when he has a moment.
I’ve gotta speak with John.
Must is used for past, present, and future expressions of necessity. Have to, on the other hand, is only used for present and future. The past tense version of have to is had to:
I had to speak with John last night.
The negative versions of have to and must have different meanings. Do not have to expresses a lack of necessity. Must indicates a prohibition, something that you cannot or should not do. Compare the following examples:
I do not have to speak with John about the incident at work.
It is not necessary that I speak with John about whatever happened at work.
I must not speak with John about the incident at work.
Either I am not allowed to speak with John about whatever happened at work or doing so would be a very bad idea.
Must not is an exceptionally strong way of expressing a prohibition. Because of this, native English speakers will often try to find other, less severe ways of saying that something is not allowed. One way to do this is by using imperatives such as don’t tell, can’t tell, and better not tell in place of must not:
Don’t tell John about the incident at work.
Expressing Advisability with Modals
Should, ought to, and had better are used to express advisably. Although their meaning is somewhat flexible depending on the context of the conversation, should generally implies a suggestion. Ought to usually implies a sense of responsibility or duty. Had better falls somewhere in between these, with an added implication of negative consequences if the advice is not followed:
You should tell John about the incident at work.
It would be a good idea to tell John about whatever happened at work.
You ought to tell John about the incident at work.
It is your obligation to tell John about whatever happened at work. Perhaps John is your supervisor in this instance, and he has a right to know about the incident.
You had better tell John about the incident at work.
There may be potentially negative consequences if you do not tell John about whatever happened at work. Maybe you will get in trouble for not reporting the incident to John. Alternately, this could be a circumstance where John’s reaction to learning about the incident will be better if he hears about it from you.
The negative should not has the opposite meaning of should. However, native English speakers commonly use the contraction shouldn’t when speaking. You’ll rarely hear the full should not in everyday conversation, unless the speaker is using it to emphasize the negative:
You shouldn’t tell John. (Common casual usage)
You should not tell John. (Emphasis of the negative to eliminate any potential misunderstanding)
Like should not/shouldn’t, the negatives ought not to and had better not function as straightforward inversions of their positive forms. However, ought not to is rarely used by native English speakers.
Things get a bit trickier with the past forms of should. Should have + past participle indicates that you did not complete an action that you were advised to do. Should not have + past participle indicates that you completed an action that you were advised not to do. In both cases, the implication is that you made some kind of error or mistake:
I should have told John about the incident at work.
Telling John about the incident would have been a good idea. I made a mistake in not telling him about it.
I should not have told John about the incident at work
I shouldn’t have told John about the incident at work.
Telling John about the incident was a bad idea. I made a mistaken in telling him about it.
Could vs. Should
Like should, could can also be used to offer advice. While the advisory should offers definitive advice, could suggests options or possibilities:
I could tell John about the incident at work.
One possible option is for me to tell John about whatever happened at work. However, telling John is not necessarily the best or only option.
I could have told John about the incident at work.
In hindsight, it was possible for me tell John about whatever happened at work. For whatever reason, I chose not to do this.
Be supposed to expresses the idea that someone expects some future event to happen. It can also be used to express expectations about future behavior. When used in the past tense, be supposed to expresses unfilled expectations:
The meeting is supposed to begin at 7am.
I expect that the meeting will begin at 7 o’clock in the morning.
I am supposed to go to the meeting.
I am expected to attend the meeting.
I was supposed to go to the meeting.
I was expected to attend the meeting, but I did not go.
Future and Unfulfilled Intentions
Am/is/are going to is used to refer to expectations for future events:
I am/I’m going to go to the concert in March.
Mary is going to go to the concert in March.
Angel and Mary are going to go to the concert in March.
Was going to and were going to, on the other hand, refer to past intentions. Usually this refers to something that someone planned to do, but for whatever reason, did not do:
I was going to go to the concert, but I had car trouble.
Angel and Mary were going to go to the concert, but they could not find a babysitter.
Let’s, the contraction of let us, is frequently used to make highly informal suggestions in spoken English. The negative form is made simply adding not. Both the positive and negative are followed by the simple form of a verb:
Let’s go to the concert. There are still tickets left.
Let’s not go to the concert. Let’s save our money for another event.
Why don’t is also commonly used in spoken English to make informal suggestions:
Why don’t we go the concert?
Why don’t we skip the concert and save our money instead?
Another way to make a suggestion is with shall + I/we. This method is considered relatively formal in modern American English. You’ll generally hear native speakers use it much less often than let’s and why don’t:
Shall I go to the concert?
Shall we not go to the concert and rent a movie instead?