naive vs naif

naive is not a noun while naif is a noun.

Word	Noun	Adjective	Verb	Adverb
naive	No	Yes	No	No
naif	Yes	Yes	No	No

As adjectives, naive and naif are synonyms defined as:

naive and naif: marked by or showing unaffected simplicity and lack of guile or worldly experience

naive (noun)	naif (noun)
	a naive or inexperienced person

naive (adjective)	naif (adjective)
marked by or showing unaffected simplicity and lack of guile or worldly experience	marked by or showing unaffected simplicity and lack of guile or worldly experience
not initiated; deficient in relevant experience
inexperienced
lacking information or instruction
of or created by one without formal training; simple or naive in style