''non'' Vs ''not''

Question

İs there any particular rule for choosing which one to use (not or non) in a sentence .

(I have searched but could not find !!!)

The fact that being idiomatic use (not or non) is changing depending on the adjective being used in the sentence.

Which sort of adjectives are ok with ''not'' which sort of adjectives are ok with ''non'' ?

For example;

With the use of adjective ''beatiful'' ''not'' is the idiomatic one.

1a) She is not beatiful

1b) She is nonbeatiful .

''NOT'' is the idiomatic one.

However, with the use of adjective ''existent'' , ''non'' is the idiomatic one.

2a) Wildlife is virtually not existent in this area.

2b) Wildlife is virtually nonexistent in this area .

''NON'' is the idiomatic one

Answer 1

Adjectives and not are two separate issues. Not is not a word used in front of an adjective necessarily. It is used to create a negation, not an adjective.

A single word: check in a dictionary

• nonexistent is a single word, you have to look up a word like that to check. There is no single rule about that. Another one is: nonsense. Sometimes, the meaning changes when there is non as in nonsense.

• not is used in negative forms of verbs even though the verb is not always expressed: The book is not interesting. They are all invited but not him. [He is not invited.]

  This example is good to show that in some cases, a negative adjective can be formed with un: uninteresting, unintelligent, unseen, unknown. Each of those can also be expressed as: not interesting, not intelligent, not seen, and not known.

In these examples:

2a) Wildlife is virtually not existent in this area. [wrong] Corrected sentence: Wildlife, virtually, does not exist in this area.

2b) Wildlife is virtually nonexistent in this area. [right]

As a general idea: "The book is nonexistent." uses an adjective. "The book does not exist." uses a negative verb form with requires not.