Modal Verbs: could

Modal Verbs: could

Could can be used with the indefinite infinitive to express past actions. When using could in this way, it usually indicates ability or possibility in the past.

Modal Verbs: can

Modal Verbs: can

Can is a modal verb that can be used to indicate ability, permission, or possibility. Here's how it can be used in different tenses and forms: present, future, indefinite passive, indefinite infinitive

Modal Verbs: ought to

Modal Verbs: ought to

Ought to is a modal auxiliary verb that is used to express obligation or duty. It is often used to suggest a moral or ethical obligation, rather than a legal obligation

Modal Verbs: must

Modal Verbs: must

Must with the indefinite infinitive is used in the present to express a strong obligation, necessity or deduction.   Examples: I must study for my exam. (strong obligation)