Which one is better and suitable about meaning:
- I believe that our manager has just signed a contract
- I believe that our manager has just been signed a contract
Also, is that passive or active voice in this sentence?
Compare with the present tense:
He signs a contract
He was signed a contract
The second of these is incorrect grammar. A passive form would be "A contract was signed by him". But there is no reason to use passive here.
So only "I believe that our manager has just signed a contract" is correct.
It would also be possible to say "I believe a contract has just been signed by our manager" but there is no need for the passive in this context.
The transitive verb sign is not like the verb give.
He signed the contract.
He gave his sister a book.
The verb sign takes a single direct object, here, the contract.
The verb give can take two objects, one of them being that which is given (here "a book") and the other being the entity to whom the thing is given (here "his sister").
We can restate these examples in the passive:
The contract was signed by him.
His sister was given a book by him.
This ungrammatical sentence:
Our manager was signed a contract NO
presumes an active voice form like this:
Someone signed our manager a contract. NO
But such a form does not exist, as signed does not work like that, taking two objects, although give does take two objects:
Someone gave our manager a contract.
Our manager was given a contract by someone.
Our manager has been given a contract by someone.