›used with the present participle of other verbs to describe actions that are or were still continuing: Where are you going?How long have you been sitting there?He was standing by the window.He's working at the moment.
›used with the present participle of other verbs, and sometimes after a modal verb, to describe actions that will happen in the future: I'm going to France next week.I'll be coming back on Tuesday.
›used with the past participle of other verbs to form the passive: He was injured in a car crash.The results will be announced next week.
›used in conditional sentences to say what might happen: If he were to offer me the job, I'd take it.
›used to say that someone must or should do something: You are not to see him again.
›formalused to show that something has been organized: They are to stay with us when they arrive.