Few expressions are so often denounced as “like” - as in “Suppose we like, just turn that idea upside down...”
After I first moved to California, I started saying “like” a lot. I think it's unfortunate that spoken British English has no real equivalent. One British friend, after I started saying “like,” asked me in bemusement, “What exactly governs when a Californian says 'like'?” At the time I didn't have a clear answer.
Manfred Wolf writes in Almost a Foreign Country that “like” marks a shift from commentary to performance. After "like" --
“We get the direct quote rather than the indirect comment on it. Dialog is replayed rather than summarized. The story is not reported so much as it is rendered. Even speechlessness is mimed.”
“This kind of talk attempts to show rather than tell. Especially among young people, speech is turning toward performance. We're asked to hear, to experience, the speaker's astonishment.”
I think “like” can also send the signal “try to emotionally intuit what I'm getting at here, rather than pedantically pick my words apart.” Used this way, “like” facilitates creative conversation, by permitting you to float untested ideas -- something that's very hard to do with educated Brits, since they've been conditioned to seize on the weakest point of an argument and then sarcastically demolish it. That can be a helpful approach, but sometimes I want to say “this concept's still in alpha mode, and probably doesn't quite fly, but I suspect it's worth playing around with."
“Like" can convey all that... Perhaps, nowadays, I don't say it often enough...