Before we talk about what a semi-modal verb is, you should be familiar with the concept of a modal verb.
What is a semi-modal verb?
A semi-modal verb is similar to a modal verb. In fact the prefix semi– means “half” or “partially”. In this case a semi-modal verb is partially a modal verb and partially not. But what does that mean?
A modal verb has certain characteristics:
- they modify the meaning of other verbs but do not have their own meaning
- it is defective – they do not have a present participle (-ing) or past participle (sometimes -ed) form
- the verb that they modify follows the modal verb in the bare infinitive (unconjugated without the preposition ‘to’) form
- subject-verb inversion for questions and negatives (do not use the word ‘do’)
A semi-modal verb follows some but not all of these principles.
Some examples include (click the links to view more information on the individual semi-modal verbs):
So when do you use them?
Semi-modal verbs can be used where modal verbs are used to show modality. In simple terms modality shows what a someone believes, intends or wants. In fact there are often semi-modal verbs that are equivalent to modal verbs.
Additionally, there are certain situations where semi-modal verbs are used instead of modal verbs, such as the for an obligation in the past (for example, must doesn’t have a past tense, so we must use had to).
Here is some further reading that may be of interest:
Want to learn more about modal verbs? You can find a guide to all the modal verbs here: introduction to modal verbs. You can also learn more about other English language information on my Teaching English page.