Learn English – Change into passive voice

In most cases, it doesn't matter terribly much whether you say "a passive verb" or "a verb in the passive" or "a verb in the passive voice" or "a verb with a passive construction". (Strictly, there isn't necessarily just one passive construction, e.g. you might say that "They were hurt" and "They got hurt" are two different passive constructions.)

To be in the active voice, the sentence needs a definite subject. That is, you need to say who opens the door. If you don't know who does it, you could use:

Somebody opens the door.

Sentences like "the door is opened" can be parsed in two ways: as passive voice present tense, or with "opened" being an adjective and "is" a copular verb. This parsing can be made unambiguous in several ways; for example "the door is opened by remote control" can only be passive voice. One way to put this sentence into active voice is "you open the door by remote control".

For the second parsing, it's not in the passive voice, and in this case, the meaning is the same as

The door is open.

The verb "is" cannot be put into passive voice, because only transitive verbs can be put into passive voice.