using past tense verbs like opened

Question

I'm struggling with the following sentences, I've seen some examples of them but it's still not clear to me.

1. This sentence means the door is in the proces of opening.

the door is being opened.

1.1. Does this also mean I can completely replace the sentence with the following and it would still mean the exact same thing?

the door is opening.

2. does this sentence mean the same as the first?

the door is opened.

3. Does this sentence mean the door used to be open or the door is still open? I believe this means someone opened the door a while ago and it is still open right?

The door was opened.

4. Now i'm not quite sure what to use anymore, should it be:

the door is/has been opened for too long.

the door is/has been open for too long.

to me the first sentence sounds better but i have no idea what the rules for this are. Since open is an adjective and opened is the past tense of a verb.

Answer 1

the door is being opened.

Someone is opening the door.

the door is opening.

The door is opening, possibly by itself.

the door is opened.

Someone has opened the door.

The door was opened.

Someone opened the door in the past.

The difference between "to be opened" and "to be opening" is the use of passive voice vs. present progressive. Passive voice reverses the order of the subject and the direct object in a sentence, so that you may draw your attention to the object being acted on, or just make it vague who did the action:

I opened the door.

The door was opened (by me).

When you use passive voice you imply that the door was acted on by someone. But if you use the progressive tense, you say that something is happening in this moment:

The car is moving

The cat is walking

The door is opening

The light is blinking

And so on.

the door is opened for too long.

the door is open for too long.

These two are different, since they imply an action or a condition that happened in the past and is still going on in the present. In this case the present perfect tense seems the best to use:

the door has been open for too long.

We would not usually say "the door has been opened" because "to be opened" is an action, a discrete moment in time. Instead you want to refer to the condition the door is in (open or closed).

As a side note, it is possible to use the present perfect with "open", but since this is kind of odd we would normally draw attention to who is doing the opening, (and question why he's taking so long to do it). So we would use the present perfect continuous instead:

He has been opening that door for far too long.

Weird, but grammatical. Another example:

He has been (out) walking the dog for far too long.