nominal clause

A nominal clause is a group of words with a conjugated verb in it that acts as a noun. Also called a noun clause, this structure can fulfill virtually all functions of a noun. A nominal clause starts with words like that, the fact that, whether, when, and many other subordinating conjunctions.

Here's one nominal clause serving some of the noun roles: The fact that you visited Grammar.com.

The fact that you visited Grammar.com shows your interest in good writing. (nominal clause acting as the subject of the sentence).

The reason you got a raise is the fact that you visited Grammar.com. (nominal clause acting as the subject complement after the verb to be)

In your review, your boss mentioned the fact that you visited Grammar.com. (nominal clause acting as the direct object of the verb mentioned)

Your boss was aware of the fact that you visited Grammar.com. (nominal clause acting as the object of the preposition of)

As a matter of style, you should try to reduce your use of the fact that. I use it here simply as way of illustrating the functions of a nominal clause. Often you can delete the words the fact and just use a nominal clause beginning with the word that. You could delete the fact in all the above examples except the last.