Mohammad Abdullah,

Semi-Modal Auxiliary Verbs Definition

Semi-modal auxiliary verbs, often simply called semi-modal verbs, are verbs that sometimes behave like modal auxiliary verbs. (They are also sometimes known as marginal modal verbs.) Like the “proper” modal verbs, they are used with the base form of verbs (the infinitive without to) to create a unique meaning.

Dare, need, used to, and ought to

Not all sources agree on the complete list of semi-modal verbs, but there are four that are widely considered as the standard set: dare, need, used to, and ought to.

Dare and need are considered semi-modal because they can also function as main verbs, able to take nouns and infinitives as objects and to conjugate for person, tense, and number. Ought to and used to, while unable to be main verbs, are considered semi-modal because they are always followed by infinitives (compared to “true” modals, which can never be followed by infinitives).

As semi-modal verbs, these verbs are used in conjunction with “main” verbs to create a complete verb expression; they do not conjugate for third-person singular subjects; they do not have a simple past tense; and they cannot form infinitives, present participles, or past participles.

We’ll look at each of these verbs individually, examining when and how they function as semi-modal verbs.

Dare

When dare is used as a semi-modal verb, it means “to be brave, reckless, or rude enough to do or try something.” Remember, when functioning modally, it does not conjugate for person or tense. For example:

• “If he dare cross me again, I’ll make sure he pays dearly for it.”

As a semi-modal verb, dare more often takes not to form a negative statement (very rarely contracted as daren’t), or is inverted with the subject to form an interrogative sentence. For example:

• “I dare not press the issue any further.”
• “How dare she talk to me like that?”
• “Dare he meddle with the laws of nature?”
• “They daren’t give him a reason to be angry.”

However, with the exception of the now idiomatic phrase “How dare (someone),” the use of dare as a modal verb has become rare in modern English.

As a main verb

Dare can also be used as an intransitive main verb with the same meaning as the modal version. When it functions as a main verb, however, it is able to conjugate for person and tense, and it can be followed by a verb in either its base or infinitive form (the to becomes optional). For example:

• “I can’t believe he dared (to) stand up to the boss.”
• “No one dares (to) question my authority!”

When dare is used as a main verb, it must take the auxiliary verb do to form questions or be made negative. As we saw in the section on primary auxiliary verbs, it is do, rather than the main verb, that conjugates for tense, person, and number in this case. For example:

• “Did they dare (to) go through with it?”
• “He doesn’t dare (to) argue with the principal.”

Dare can also mean “to challenge someone to (do) something that require courage, boldness, or recklessness,” in which case it must take a noun, pronoun, or infinitive as a direct object. It cannot be used modally with this meaning. For example:

• “I dare you to ask Suzy on a date.”
• “I’ve never been dared to race someone before.”

Need

Need as a semi-modal verb is almost always used in negative sentences to express a lack of obligation or necessity, either taking the adverb not (usually contracted as needn’t) or paired with a negative word or phrase, such as never, no one, nothing, etc. For example:

• “No one need know about this.”
• “He needn’t have called; I told him I would be late.”
• “You needn’t worry about my grades.”
• “Nothing need change simply because my father is no longer here.”

It can also be used to form interrogative sentences by inverting with the subject, as in:

• “Need we be concerned?”
• “Need I go to the market later?”

Like dare, though, the modal use of need has become quite uncommon in modern English, except in very formal speech or writing.

As a main verb

Need is much more common as a main verb. This means it conjugates for person (becoming needs in the third-person singular) or tense (becoming needed), and it uses auxiliary did to form negatives and questions. As a main verb, need can be followed by nouns, noun phrases, pronouns, gerunds, or infinitives. For example:

• “He needs that report by tomorrow.”
• “Does she need to know where the house is?”
• “You have plenty of time, so you don’t need to rush.”
• “He needed a place to stay, so I offered him one.”

Source: The Farlex English Grammar Book By Peter Herring.