English Grammar: Modality

Modality Although some grammarians consider it to belong to the category of MOOD, modality actually stands on its own, particularly in the English language where it is primarily marked by the system of MODAL VERBS. If we compare the following sentences: 1. It is raining. (INDICATIVE; marks the statement for the factuality of action/state/event described by it) and 2. It may be raining outside. (MODALITY) we can define MODALITY as the way in which the …

…as a modal "need" takes perfect infinitive to denote past: You needn't have hurried so. "Have to" has the following meanings: 1. external obligation, especially as the past tense of must: He had to go yesterday. 2. dynamic necessity: The plants have to receive plenty of sunshine to grow. 3. instead of "need" meaning necessity: You'll have to hurry if you want to catch that train. "Have got to" expresses same meanings, reinforcing the idea of external authority.