Functions of the English auxiliary verb

Passive voice
The auxiliary verb be is used with a past participle to form the passive voice; for example, the clause "the door was opened" implies that someone (or something) opened it, without stating who (or what) it was. Because many past participles are also stative adjectives, the passive voice can sometimes be ambiguous; for example, "at 8:25, the window was closed" can be a passive-voice sentence meaning "at 8:25, someone closed the window," or a non-passive-voice sentence meaning "at 8:25, the window was not open". Perhaps due to this ambiguity, the verb get will sometimes be used colloquially instead of be in forming the passive voice, "at 8:25, the window got closed".