“Nais” means “desire” or “wish”, while “gusto” means “like/want”. Although “nais” is no longer a popular word now, it may be used in place of “gusto” to mean, “like/want/desire”. I already want/would like to sleep now. = "Gusto/Nais ko nang matulog ngayon." (In this sentence most of us would use “gusto”, although it won't be wrong to use ”nais”.) If “wish” is the meaning you specifically intend to convey, it would be more appropriate to use “nais”. I want to become rich someday. = "Gusto kong yumaman balang-araw." (This would suggest greed). I wish/would like to become rich someday. = "Nais kong yumaman balang-araw." (This would sound hopeful).

"Gusto" is from Spanish and more colloquial. "Nais" is older Tagalog and is more formal/ literary. They are conjugated the same way.

I think, technically, there's no difference as both mean the same thing which is "to want." But to me, "nais" sounds a tiny bit more polite than "gusto" depending on the context.

Maraming salamat, Henry!

Kaiasa -> Kaysa. Mapapansin mo lang naman ang pagkakaiba ng "kaibhan" at "kaibahan" pag ang mga ito ay binigkas ng mabagal. Pero sa normal na pagsasalita namin, pareho lang ang tunog nila. Sa pagsulat naman, kahit alin sa kanila, pwede. Kaya OK lang kung mas gusto mong gamitin ang "kaibhan" kaysa sa "kaibahan". May kasabihan nga kaming mga Pilipino - "kung saan ka masaya". :-)