Why to avoid using noun together with "it"?

It is a pronoun, which means it replaces a noun. Because it functions just like the noun that it replaces, you should not use it with a noun preceding or following it. You should only use it if it's clear which noun you are referring to.

Incorrect: The cat it drank milk.

Correct: The cat drank milk.

Correct: It drank milk.

A pronoun is a word that replaces a noun. It is a type of noun, and it functions just like a regular noun. It is a pronoun that replaces a singular, non-human noun. It follows the grammatical rules of the third-person singular point of view. Because it is a pronoun, you do not put the associated noun next to it. It takes the place of the noun completely. However, it must be clear to your readers what noun you are referring to, so make sure you have used that noun in a nearby sentence.

Incorrect: The chair is an antique. The chair it belonged to my grandmother.

Correct: The chair is an antique. It belonged to my grandmother.

Incorrect: The volume is too loud. Turn it the volume down.

Correct: The volume is too loud. Turn it down.

Like most English grammar rules, there is an exception. Sometimes, the noun can precede the sentence that uses it for added emphasis. This is not used in formal or technical writing, and it should only be used in creative writing sparingly. You must also put a comma after the noun and before it.

Example: The wine, it is delicious.