Similar to modals verbs, quasi-modal verbs are common auxiliary verbs in the English language that express modality, which is the expression of subjective attitudes and opinions including possibility, necessity, and contingency. Also referred to as semi-modal verbs, the four quasi-modal verbs in English are:
- ought to
- used to
- would rather
- had better/best
Position of Quasi-modal Verbs
Like modal verbs, quasi-modal verbs always appear in the initial position at the beginning of a verb phrase functioning as a predicate. The seven possible English verb phrase combinations that contain quasi-modal verbs are:
- quasi-modal verb + base form = ought to study
- quasi-modal verb + be + present participle = ought to be reading
- quasi-modal verb + have + past participle = ought to have eaten
- quasi-modal verb + be + past participle = ought to be cleaned
- quasi-modal verb + have + been + present participle = ought to have been thinking
- quasi-modal verb + have + been + past participle = ought to have been washed
- quasi-modal verb + have + been + being + past participle = ought to have been being finished
Prescriptive grammars proscribe combinations of two or more modals and/or quasi-modals. However, double and triple modals are features of some Englishes including Southern American English such as used to could as in I used to could jog a mile.
Some Definitions of Quasi-modal Verbs
Just as with modals verbs, quasi-modals are more difficult to define that prototypical verbs because of the range of pragmatic uses of quasi-modals by native speakers. Some of the more common definitions (in no particular order) of the English quasi-modal verbs are:
- ought to – should, duty, obligation, advisability, desirability, likelihood, probability
- used to – formerly, once but no longer, previously habitually
- would rather – preference, prefer to
- had better/best – should, duty, obligation, advisability
- You ought to stain your fence this year. (advisability)
- My sister used to read a book a night. (previously habitually)
- I would rather eat a bug than study math. (preference)
- She had better teach her children some manners. (duty)
Quasi-modal Verbs versus Modal Verbs
Just as pronouns are a subcategory of nouns, quasi-modal verbs are a subcategory of modal verbs. Quasi-modals resemble modals in that quasi-modal verbs also do not reflect grammatical number. For example:
- You need to study for the test. (correct)
- He needs to study for the test. (correct)
- You should study for the test. (correct)
- He should study for the test. (correct)
- *He should study for the test. (incorrect)
- You ought to study for the test. (correct)
- He ought to study for the test. (correct)
- *He oughts to study for the test. (incorrect)
Quasi-modals also lack tensed (past, present) and nontensed (infinitive, present participle, past participle) forms. For example:
- Base – Infinitive – Present Tense – Past Tense – Present Participle – Past Participle
- eat – to eat – eat, eats – ate – eating – eaten
- could – *to could – could, *coulds – *coulded – *coulding – *coulden
- ought to – *to ought to – ought to, *oughts to – *oughted to – *oughting to – *oughten to
Quasi-modal verbs differ from modal verbs in form. While full modals are single words, quasi-modals consist of either a verb plus a preposition functioning as a particle or a verb plus an adverb. For example:
- ought to, used to = verb + preposition [particle]
- would rather, had better = verb + adverb
Similar to phrasal verbs, quasi-modals are periphrastic modal auxiliary verbs. Periphrasis, as defined by the Oxford English Dictionary, is "a phrase of two or more words that together perform a single grammatical function that would otherwise be expressed by the inflection of a single word." Quasi-modals, unlike modals, consist of two elements. However, quasi-modal verbs otherwise function identically to full modal verbs.
Note, however, that the quasi-modal verb ought to sometimes lacks a prepositional particle in negative and interrogative constructions. For example:
- He ought to buy a new car.
- He ought not buy a new car.
- Ought he buy a new car?
An asterisk * indicates an incorrect form.
For a printable accompanying reference sheet of the four quasi-modal verbs in English, please download English Quasi-modal Verbs Reference Sheet.