Comment 1 by Michael Austin :

I'm America, many teenagers say "He was like" instead of "He said." This seems to be pretty new, I've only noticed it in the last 5 or so years.

I doubt it. No offence, but how old are you? Because my generation have been saying "He was like" since at least the early '90s, and I'm pretty sure we got it from America.

And it's not exactly equivalent to "He said". "I said" (mind if I switch pronouns?) begins a report of my actual words; "I was like" means that I am about to summarize the intent behind what I said and did next. Even if I didn't actually say anything. "So I spotted this big threatening guy looking in my direction, and I was like 'I'd better get out of here'..." may be an accurate report, even if I in fact said nothing and simply backed quickly away into the surrounding crowd.

Comment 10 by DrDroid :

The word "like" appears everywhere in the sentences uttered by teenage girls these days, at least in the USA. I'm not sure how the fad got started or what it's intended to convey. It's almost like (no pun intended) the girl is broadcasting "like me" messages into your subconcious.

"Like" as a sentence adverb has been around since at least the 1960s, when it arose in hippie culture. Along with the habit of addressing everyone as "man" it was most often used as a symbol of the many things non-hippies didn't understand, or were more interested in laughing at than understanding, about hippies. It is certainly not functionless -- no linguistic feature is -- but it is hard to analyse, I'll grant you that.

Most often, I think, "like" signals inexactitude in the clause that follows it -- "This is like what happened, as seen from my point of view, rather than an impartial, objective, or strictly accurate report."

As for "So..." introducing a topic, I know I've done this myself quite a bit, and I'm trying now to think why. I meant to convey something by it, something that would not have been conveyed had it been missing, but I'm finding it nigh impossible to articulate what that something was. It does (to me) seem to create a certain immediacy -- as if I'm dropping the reader right in the story, rather than leading them in with introductions. But I don't think that expresses it very well.