How do you add the suffix -ness to immaterial?

You can't add the suffix "-ness" to "immaterial" to form a new word.

Here's why:

* "Immaterial" already expresses a state or quality. It means "not important" or "not relevant." Adding "-ness" would be redundant.

* "-ness" typically forms nouns from adjectives. While "immaterial" is an adjective, it already functions as a noun in some contexts.

Instead of "immaterialness," you can use synonyms like:

* Irrelevance

* Unimportance

* Triviality

* Unsignificance

These words convey the same meaning as "immaterialness" but are grammatically correct and avoid the awkwardness of adding "-ness" to a word that already implies a quality.