is this grammatically correct?

These answers are amazing. At this writing, there are 46 answers that claim that this construction is incorrect. Why do 46 people who have no knowledge of English show that lack of knowledge by posting such answers?

It is perfectly correct in both grammar and usage.

The present infinitive of the verb 'do' is 'to do.'

The present passive infinitive is 'to be done' - To + be + past participle.

Now, how about this sentence:

It should be done.

Pretty normal - 'be done' is the bare infinitive - the infinitive without the 'to'. You drop the 'to' after verbs like 'should' and 'might.' You don't say 'I should to go' - You say 'I should go.'

Next, somebody does it - whatever it is.

I saw it be done. Still sound OK?

Someone else does the same thing.

I've seen it be done before.

it's grammatically correct

Yes and no. If it is intended to be done as in a physical action, then the correct form is "seen it done before". If it is a procedure that could be done at some future time. then the form is correct.

It may be better to say "I've seen it done before."

But, there is nothing incorrect about "be done".

To put it simply, Yes, it's correct, in the sense that it's not wrong.

I've seen it done before would be grammatically correct, sooo Just drop the be.

Not grammatically correct.

I've seen it done before is correct.

It's like toe-may-toe versus toe-mah-toe pronunciations. It sounds better as "I've seen it done before", but there are tons of people who put the "be" in that sentence because it sounds correct to them. But ultimately, you'll be taught that "I've seen it done before" is grammatically correct because most of the time, the less words you use...the better.

This is not grammatically correct. The proper way of saying this would be "I've seen it happen before!"

It is not grammaticall correct. Much better to say, " I've seen it done before".

No, the sentence you wrote has two verbs next to each other, but both are conjugated as if there were only one verb there.

Incorrect: "I've seen it be done before!"

Incorrect: "I've seen it been done before!"

Correct: "I've seen that it has been done before!"

Correct: "I've seen it being done before!"

Even more correct: "I've seen it done before!"

Hope this helped,

Kendra