[Grammar] Correct Usage of Prefixes

QUESTIONS....

My friend and I were having a discussion about using prefixes and suffixes to create new words.
Can anyone define endisfunctionality? Is the en prefix correct usage? Is the en- prefix and the in- prefix interchangeable or mean the same? If the 'word' endisfunctionality were used in a written essay, how would it be punctuated or written?

Any help appreciated.

Confused

[konungursvia]

They are not interchangeable, but they mean similar things at times: they both signify beginnings of actions or states, but each verb has either in- or en- (if it can take a prefix) and you must learn which one belongs to each verb. Inflame, enable, ingest, ensue... etc.