modalperiphrastic

Modalperiphrastic refers to a category of expressions in which modality is expressed through periphrasis rather than a single dedicated modal verb. The term is used in linguistics to describe systems in which auxiliary-like phrases combine with nonfinite verbs to convey necessity, possibility, obligation, probability, or ability. While many languages employ standalone modal verbs, modalperiphrastic constructions rely on periphrastic sequences, often with tense or aspect marked by the dependent verb.

Typical patterns include be + infinitive (be going to for future intention, be able to for ability, have to for obligation), have + past participle (must be interpreted as periphrastic in some contexts), used to for past habitual; these constructions can encode epistemic or deontic modality and may interact with aspect.

Examples include: I have to finish this today. She is able to complete the task. They are going to start soon. He used to visit us every summer.

In English, modalperiphrastic constructions often overlap with canonical modals, but the term helps describe a broader periphrastic approach to modality. Cross-linguistic variation ranges from languages that rely heavily on periphrastic future and obligation to those that maintain a compact set of modal auxiliaries.

See also modality, periphrasis, and auxiliary verbs.