Complex Object + Passive Voice

[kdmitriyval]

I don't understand the grammar of reason of using to be before Passive Voice in sentences.
For instance:
He wants the letter to be brought into his room.
and
He wants the letter brought into his room.

In what cases is it neccessary to use to be before Verb? I can't find a rule for this one.


Second question for continuous:
He saw the letter being written.
and
He saw the letter written.

The same question, in what cases do I need to use being before Verb?

I hope you understand my problems.
Best regards.

 

[emsr2d2]

Six of your sentences don't end with a punctuation mark. Click on "Edit Post" and complete the punctuation and then we will look at your query.