The verbs dare (= be willing to risk), need (= have to, must), ought to and used to are often treated by grammarians as modal auxiliaries.
- I daren’t tell her that I’ve forgotten to buy her a birthday present.
- You needn’t leave yet. There’s plenty of time.
- I think we ought to leave now.
- He used to live in that house over there.
There are a number of things to be noted about the grammar of these verbs.
Dare and Need
Dare and need may behave either as auxiliary verbs or as lexical verbs.
In positive statements (that is, statements without a negative word such as not or –n’t), need and dare are treated as lexical verbs and are therefore followed by to-infinitives:
- I need to check our travel arrangements.
- I cannot think how she dared to tell him he was wrong.
As lexical verbs, weed and dare have the -s ending when the subject of the verb is he, she or it:
- He needs to check his travel arrangements.
- She dares to suggest that I’m in the wrong? She’s got a nerve!
However, contrary to the general rule for infinitives following lexical verbs, the lexical verb dare is very often followed by a bare infinitive:
- I cannot think how she dares tell him he is wrong.
With a negative word such as not or -n’t, need and dare can be treated either as lexical verbs or as auxiliary verbs.
As lexical verbs they must be used with the auxiliary verb do, whereas as auxiliary verbs they are used without do.
- He doesn’t need to check the details. OR
- He needn’t check the details.
- He does not dare (to) suggest that to her. OR
- He dare not suggest that to her.
Notice that, as auxiliary verbs, need and dare do not have the -s ending when the subject of the verb is he, she or it: he needn’t; he need not; he daren’t; he dare not.
Not and -n’t are not the only negative words that allow need and dare to be treated as auxiliary verbs. Other negative words, such as no or no-one, or words with a slightly negative meaning, such as scarcely and hardly, do this too:
- No-one need fear the consequences of being absolutely honest.
- It is said that no-one dare disobey him.
- No friend of mine need ever be afraid of facing the world alone.
- He need scarcely fear that he will end up penniless.
- John need know nothing about our arrangement.
A negative word attached to a preceding verb is even enough to allow need and dare to be treated as auxiliary verbs:
- I don’t think he need worry about that.
In questions, need and dare can again be treated either as lexical verbs eras auxiliary verbs. As with negatives, dare and need as lexical verbs must be used with the auxiliary verb do, whereas as auxiliary verbs they are used without do:
- Do you need to leave so soon? OR
- Need you leave so soon?
- Do I dare (to) say that to her? OR
- Dare I say that?
And in negative questions:
- Don’t I need to leave after all? OR
- Needn’t I leave after all?
- Doesn’t he dare (to) say that to her? OR
- Daren’t he say that to her?
With not rather than -n’t, the verbs are best used as lexical verbs:
- Do I not need to leave after all?
- Does he not dare (to) say that to her?
The idiom how dare you/he/they, etc, that expresses anger at something someone has done, is always followed by a bare infinitive:
- How dare she behave like that in public?
- How dare you tell the directors I was lying?
When the verb dare is used with the meaning ‘to challenge someone to do something dangerous’, it is always treated as a lexical verb and followed by a to-infinitive:
- He dared me to do it.
- Anyone who dares a little boy to run across a busy motorway must be really stupid.
Similarly, when need is followed by an object, it is always treated as a lexical verb:
- John says he needs a new pair of shoes.
- He needs me to help him with his homework.
Like an auxiliary verb, ought has no -s ending for the third person singular of the present tense, but on the other hand it is always followed by a to-infinitive like a lexical verb:
- He ought to apologize.
The correct negative forms of ought to in standard English are ought not to or oughtn’t to:
- You ought not to do that. OR
- You oughtn’t to do that.
The question forms are ought I/you, etc?, and, in the negative, oughtn’t I/you, etc?, etc or ought I/you, etc not?:
- Ought we to be leaving soon?
- Ought we not to tell him now?
Ought to is a past tense when used in a subordinate clause in reported speech preceded by a verb in the past tense:
- She knew she ought to tell him the truth.
- I told her that she ought to speak to a doctor about her problem.
However, when referring to something which should have happened in the past but which did not happen, use ought to have:
- I ought to have been more careful.
- We ought to have said that we were coming.
To refer to something which should not have happened but which did happen, use ought not to have:
- You oughtn’t to have told him.
Used to is used to talk about something that happened frequently in the past but which no longer happens or about something that was true in the past but which is no longer true:
- I used to smoke but I stopped a couple of years ago.
- We used to go for walks in the hills every weekend but we don’t seem to have time to nowadays.
The negative forms of used to are used not to and usedn’t to:
- He used not to smoke as much as he does now.
- He usedn’t to smoke at all.
In more informal English, didn’t use to is also acceptable:
- He didn’t use to come here very often, but nowadays we see him here at least three times a week.
The interrogative forms of used to are did he/she, etc use to? and, in the negative, did he/she, etc not use to? or didn’t he/she, etc use to?:
- Did your brother use to live near here?
- Did your brother not use to live near here? OR
- Didn’t your brother use to live near here?
Used he to do it?, used he not to do it?, and usedn’t he to do it? are all also possible but are much less common.
Do not confuse the modal verb used to with the adjective + preposition phrase used to, pronounced, which means ‘accustomed to’. Notice the difference between:
- I used to live here. (= I once lived here but I do not live here any longer)
- I am used to living here. (= I have grown accustomed to living here)
Question Tags with Dare, Need, Ought to and Used to
With any of the constructions that have do, does or did in the main clause, form the tag question with do, does or did:
- I didn’t need to tell you, did I?
- She doesn’t need to go yet, does she?
- You didn’t use to like Kylie Minogue, did you?
With dare and need as lexical verbs, form the tag questions with do, does or did:
- She needs to tell him the truth, doesn’t she?
- I don’t think she dares tell him anything, does she?
Used to also forms tag questions with did:
- He used to live near by, didn’t he?
With dare and need as auxiliary verbs, form the tag questions with the auxiliary verbs:
- We needn’t tell him anything about it, need we?
- She daren’t say anything to him, dare she?
Ought to forms tag questions with ought:
- She ought to be here by now, oughtn’t she?
- We ought not to be here at all, ought we?