Just wondering out loud how one would analyze the morphological role of the -o in neato? It's a word I used near constantly when I was ten
Wiktionary actually has a page on this (duh, there's a wiki page for EVERYTHING!) and they list a group of words using an -o morpheme, but they don't really form a natural class: bucko, cheapo, daddy-o, kiddo, lesbo, neato, preggo, righto, sicko, wacko, whammo, wino, weirdo, yobbo.
I've never heard of some of these words (yobbo?), but even with those I do recognize, they do not seem to fall into the neato class. The Online Etymology Dictionary claims neato's earliest recorded usage was 1968, but gives no citation.
My dad used to say el cheapo and I can buy the Wiktionary claim that it's a pseudo-Spanish homage (I don't know what else to call that kind of construction), but did neato form that way? I have a hard time believing that daddy-o formed that way. Again, the Online Etymology Dictionary claims daddy-o goes back to 1949 (from "bop talk", I love that phrase).
el cheapo is an interesting construction too. Are there other examples where we take a foreign morpheme* and adopt it as a signifier in this way?
*Let's ignore the question of whether or not there really is an -o morpheme in Spanish. Somewhere along the lines American English speakers believed there was and adopted it.