The man we are talking about is coming.

This is a story that I have never heard before.

This is just a story that I have never heard before.

I bought a bike that I don't like.

I bought a bike that I don't like.

The man who has been to many countries in the world is my father.

The man who has been to so many countries is my father.

This is the best film I have ever seen.

This is the best film I have ever seen.

It was my brother who called me yesterday.

The man who called me yesterday is my brother.

I can't see the boy playing basketball.

I can't see the boy playing basketball.

Because you are talking about attributive clauses, try not to omit conjunctions!