Modal verbs and substitute forms in contexts
How it works
Modal verbs such as ‹can›, ‹must›, ‹may›, ‹should› and their substitute forms (e.g. ‹be able to›, ‹have to›, ‹be allowed to›) express abilities, necessities, permissions, advice, and possibilities. In some tenses or grammatical constructions, substitute forms are used instead of the actual modal verbs, e.g. often ‹was able to› instead of ‹could›, when a single successful action in the past is meant. The choice of the correct modal or substitute depends on the context, the tense, and the meaning. Example: For a successful action in the past: ‹She was able to finish the test.› For an obligation: ‹You have to wear a uniform.› Modal verbs are not conjugated and stand before the full verb in the infinitive. Substitute forms are conjugated like normal verbs.
Choose the appropriate modal verb or the correct substitute form according to context, tense, and meaning. Note that modal verbs do not take endings and stand directly before the infinitive, whereas substitute forms are conjugated.
An example
‹Which sentence correctly expresses a single successful action in the past?›
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50 Exercises
To the learning unit →Own explanation and own practice exercises by AmyMath. Subject reference framework: English. The topic assignment may vary by federal state.