Mesthrie et al. (Introducing Sociolinguistics 2nd ed., 2009:117-8) discuss “three newer uses” of like, the “quotative” use (I’m like why did you do that), the use of like as a hedge (My parents like hate you) and the use of like as a discourse particle (I‘m like really struggling with this assignment).
The origin of these new usages the authors trace back to “Valley Girl speech”, popular in the 1980s, but still so today.
But we find examples of this usage already in novels by Kingsley Amis:
- this old like parchment says any motherfucker digs me up (Jake’s Thing, 1978)
- I mean, you know, like really believe it? (Jake’s Thing, 1978)
And even earlier than that, in One Fat Englishman (1963):
- Or rather … find, like, seem to think she wanted to stick to?
In this novel Amis contrasts British with American ways, regularly commenting on language in the process. In doing so, would he have picked up an earlier instance of usage? Even the instances in Jake’s Thing suggest that the newer usage was already in evidence before the 1980s.
Bridging the Unbridgeable 
That’s really interesting. The OED (OED1 and 2 – the entry for ‘like’ hasn’t been updated yet) groups such uses under sense 7:
dial. and vulgar. Used parenthetically to qualify a preceding statement: = ‘as it were’, ‘so to speak’. Also, colloq. (orig. U.S.), as a meaningless interjection or expletive.
(I’m sure the OED3 definition will be a lot more objective…)
The first quotation is 18th c. British:
1778 F. BURNEY Evelina II. xxiii. 222 Father grew quite uneasy, like, for fear of his Lordship’s taking offence.
Do you have any early examples of quotative ‘like’? (These aren’t included yet in the OED entry.) I had a look in the Corpus of Historical American English, and the earliest examples I could find were from the 1980s (e.g. John Jakes, 1987, Heaven and Hell: “And I was like , What have they done to my boy over there?”) Are there any examples like this in Amis?
Sorry, I must correct the comment above – there’s a draft addition at the end of the OED entry which does cover quotative ‘like’, dating it to 1982 (in Zappa’s ‘Valley Girl’). Still, no harm in looking for antedatings!
“Like” was used at least as early as the 1940s and 1950s by hip-talkers. It often began a sentence. US comedian, Stan Freberg, speaks a good example on his 1953 album “A Child’s Garden of Freberg” when, acting the part of a jazz musician called in to do studio work on a tiresome pop song, says “Like, wow!” when asked a question he found hard to answer.
It is interesting to read Paul Bennett’s comment on the origins of “like”. In the cartoon series “Scooby-Doo: Where are You?” (first aired in 1969), the character Shaggy frequently intersperses “like” in his speech, as in “Like, gangway!” or “Like, there’s this green monster, officer, sneaking around at the old cotton mill, we’re heading out there to meet the gang and, like, catch it!” The character’s voice was acted by Casey Kasem (born 1932), who was a radio personality at the time. Bennett’s comment makes me wonder whether the origins of “like” were possibly popularized through television/radio channels and/or personalities such as Freberg and Kasem (“Shaggy”). Shaggy also frequently starts his sentences with “like”.