I recently went out with a guy who threw a gratuitous "you know?" into every five seconds of conversation, a tic that swiftly brought me to the conclusion that he was unintelligent. My assumption turned out to be false, but, you know, his convoluted way of speaking was seriously off-putting.
To be clear, I'm no linguistic elitist (or worse, prescriptivist). I'm a supporter of colloquialisms, especially if they contribute an extra layer of complexity, as they so often do. For example, in the above paragraph, I included the word "seriously," which is a classic case of excessive adverb usage, and frankly, I'm okay with that. Had I followed traditional grammatical guidelines and written, "his convoluted way of speaking was off-putting," my criticism would have seemed more severe than I intended it to be. Adding the word "seriously" served a purpose; it didn't just muddy up my sentence, but helped shape it into a multifaceted claim. His convoluted way of speaking was off-putting, but I wasn't, like, upset about it. Which brings me to my next point: sometimes, the oft-criticized use of "like" is more than a wrist-slap-worthy faux pas.
Allan Metcalf recently defended the way we use "like" in The Chronicle of Higher Education. He writes:
"[It] allows us to introduce not just what we said or thought, but how. Instead of merely saying words, 'like' with 'be' allows us to enact the scene. And that, I think, is because it's an extension of a longstanding use of 'like' to indicate manner: March came in like a lion, He raged like a madman."
Marc Tracy at The New Republic couldn't disagree more, stating, "We don't always use 'like' with such high-minded intentions." This is true: sometimes we use "like" as a so-called filler word (as in, "I, like, hate Mondays"). This, I would argue, can also be acceptable.
The linguists who aren't pulling their hair out over "like" have at least been scratching their heads over it for a few decades now. Its spurt in popularity is usually linked to the young, affluent women growing up in the San Fernando Valley in the 80s ("Valley girls"), who used it along with a slew of other phrases such as "totally" and "gnarly." Thankfully, the rest of the nation hasn't taken to using "hella" as an emphasizer, but, perplexingly, much of the world has taken to "like" as a conversational hedge.
"Like" can serve two important, or at least forgivable, functions. The first is to allow a certain tentativeness to a spoken thought. Extroverts, like "Valley girls," are prone to thinking while they speak rather than before they speak, which means their language is more likely to include filler words, used while thoughts are being formed.
The second purpose is a hairier one to defend. A more deliberate use of "like" is to intentionally insert it into a statement in order to soften the claim's blow -- sort of like a euphemism (again, as in, "I, like, hate Mondays"). Adding "like" to the statement "I hate Mondays" nods to the claim's harshness and absurdity.
Like it or not, irony has become an "ethos of our age." On one hand, a lack of earnestness makes a speaker seem vapid -- they've nothing substantive to say, so they rely on sarcasm or ridicule. On the other hand, speaking and living with a healthy dose of irony is a way of conveying self-awareness. You can say that you "like, love watching 'The Bachelor'," which is to say that you sincerely enjoy the show, but also know that it's a silly waste of time.
Speaking this way could be interpreted as sardonic or lazy, but it's also a quick means of dictating two conflicting but coexistant viewpoints. It's easier to say "I, like, hate Mondays" than to say "I hate Mondays the way I hate meatloaf; both are minor annoyances that are difficult to stomach." Speaking shouldn't be as ornate and time-consuming as writing. When it is, it comes across as canned or false (imagine saying the latter Monday analogy out loud to your coworkers). Vladmir Nabokov said, "I think like a genius, I write like a distinguished author, and I speak like a child," and there's something to this. Both writing and conversation are arguably more interesting when they involve dualities, but in writing, duality manifests itself as intricate wordplay, punning, or metaphor. In speaking, dual meaning often comes from colloquialisms, like "like."
Of course, there are exceptions. It'd be ridiculous to say, "It's, like, 38 degrees outside" when it's actually 38 degrees outside. This usage treads into "you know?" territory, which is, you know, seriously off-putting.