I so enjoy being a citizen of the living and in fact sweaty smelly and horny English language. Here are some favorite neologisms of my adult years.
“I Was Like” · I remember the first time I noticed this, in an early-Web-era chunk of trash-TV commentary, and remarking how instantly comprehensible it was. “I was like, he really shouldn’t have done that.” The comma is weak there (but typographically and grammatically helpful), much stronger in usages such as “She was like, ewwwww.” This has totally overrun the territory formerly occupied by “I said, in effect, ...”, “along the lines of”, and related idioms.
I haven’t seen a serious etymological study, but I suspect it derives vigor from the late-beatnik/early-hippie usages of “Like” which have survived and are now lodged deeply in mainstream formulations such as “They must have spent like millions on that”.
But it has a very specific grammatical formula which I think didn’t exist in the Seventies but did by the early Nineties, a plausible first occurrence perhaps already uncovered by an earnest scholar of modern English. If not, a prize awaits one of those.
This also means that there are many living, and reading this, who cannot remember a time when this wasn’t part of the language.
“Woah” · It’s everywhere and only crossed my radar after the dawn of Twitter. Online research quickly uncovers assertions that it’s an alternative, perhaps simply erroneous, spelling of “whoa”, but I’m unconvinced.
It feels to me like an expletive, natural to the native speaker of modern English, emanating from a location related to “Wow” and perhaps with a flavoring of “Oh”; conveying amazement without suggesting that anyone stop what they’re doing.
I suspect that this is actually a rather pure neologism, of the best possible sort, where literate people capture what they hear being said (maybe by themselves) and just write it down onomatopoeically without worrying too much.
“More So” · This one is subtle, and it’s definitely got a class dimension, where by “class” I mean “How much education you got, influenced by how much your parents did.” I hear things like “It was horrible, even more so than what happened to Dave.” Many well-educated Anglophones just wouldn’t include the “so”; but it’s compelling.
It’s not that new; I observe that there are (often disparaging) entries for the single word “Moreso” in online dictionaries, but I never see this usage written, and my ears hear it as two words. They hear it a lot recently, in sentences that surprise but sort of please my ear. Check the discussions at Grammarist and Language Log, both of which consider the combined form an accomplished fact.
I think this usage is well on its way to entering the written mainstream simply because its flavor pleases, but I bet that when that happens, it remains a two-word more so than one-word construct.
There Are More · Lots; I’m just cherrypicking from what I hear day-to-day. English is a big loud vigorous animal, still in its youth.