Die gängigste Form Befehle und Verbote auszusprechen ist der Imperativ. Darüber hinaus kann auch das Verb must (not) herangezogen werden oder auch die Ersatzform have to.

Verb Beispiel
must I tell you, the men must be finished with the work by Monday noon.
have to You were told that you had to return home immediately.
must not One must not smoke in public buildings.

Auch hier wieder gibt es viele Möglichkeiten, sich von den Modalverben zu lösen.

Verb Beispiel
to be (not) to We are to clean the kitchen after we used it. (Befehl)
You are not to take the dog into the supermarket. (Verbot)
to be not allowed to He is not allowed to have a cat in his apartment. (Verbot)
to not allow Her father does not allow her to have a motorbike. (Verbot)
to be not permitted to They were not permitted to use the toilet during the exam. (Verbot)
to be not supposed to People are not supposed to steal. (Verbot)