On the broadest of spectrums, language can be broken down into two categories:

There’s the content side of language – that is, the part of language that allows us to picture things in our heads. These are your nouns, verbs, adjectives, and adverbs. And this side of language is perpetually growing, because the world is perpetually changing. In some cases, an existing word can develop a new definition (like “tweet” and “text”). In other cases, entirely new words are created (like “Netflix” and “ringtone”) to fit the times. The content of language is made to grow and change parallel to the people that use it.

But the other side of language – the function side – is not nearly as liberally inclined as its counterpart. These are your pronouns, prepositions, and conjunctions. To be a function word is to be a member of a very exclusive, tradition-oriented club. Words like “they” or – well, “or” – serve very specific purposes within language. As such, the function of language is notably more static than the content of language. The players on the field may change, but the rules tend to stay the same.

That’s because it’s hard to change the rules! Imagine if America’s top team of linguists announced tomorrow that a brand new pronoun has been added to the English language: “smee.” They would tell you that “smee” is a gender-inspecific singular pronoun, meant to sit alongside “he” and “she”. Would you start using the word?

The truth is, you probably wouldn’t. You’ve survived this long without the word “smee,” you’d think. No need to fix what isn’t broken.

So how on earth did an entirely new language device – one with a great deal of new, uncharted function – become accepted by the entire world?

Frankly, I’m not really sure. #letstalkaboutit.

#Origin

Of course, the “#” symbol existed long before Twitter. It’s had a variety of non-language uses: it designates numbers (“We’re #1!”), tells musicians to raise a pitch by a half-step (“Play an F#.”), and plays a role on most telephones (the “pound” key). The symbol itself has served some function or another for hundreds of years.

But it wasn’t until Twitter came along that the symbol found a place in the digital age. This fateful tweet from Chris Messina in 2007 is allegedly the first occurrence of the “hashtag.” The idea was simple: by placing a “#” symbol directly in front of a word or phrase, a tweet would be classified into a group. For example: if I tweeted,

This #pizza is delicious!

The word “pizza” would link me to EVERY tweet about pizza. Ever.

The hashtag was a brilliant idea – and it gained steam during the 2007 California wildfires, in which San Diego resident Nate Ritter included the hashtag “#sandiegofire” in every relevant tweet. Eventually, use of the hashtag spread like – well, wildfire.

#Evolution

Languages evolve. But typically, the rate of evolution is slow enough to be virtually undetectable. This was not the case with the hashtag.

The grouping tool was eventually picked up by all sorts of social media outlets: Tumblr, Instagram, and most recently, Facebook. Businesses have begun to identify the marketability of the hashtag. But while all this high-profile hubbub has been happening, the masses – everyday social networkers like you and me – have fully integrated the hashtag into our online vernacular. Oh, and not just as a means of grouping topics.

Certainly, that’s still a primary function of the hashtag. As I write this, the current hottest “trends” on Twitter are as follows: #sometimesiwishthat, #MentionSomeoneWhoHasAPrettyFace, and #prayforTexas. All of these hashtags are functioning as its creators intended.

But more subtle, nuanced uses of the hashtag have emerged in recent months and years. Someone might tell an embarrassing, 140-character story, and close it with #oops. Someone might put the punchline of a joke inside a hashtag. Recently, television producer Damon Lindelof tweeted:

The hashtag is the modern day equivalent of the Shakespearean aside. Discuss. #DoNotDiscuss #YouHaveBetterThingsToDoWithYourTime

Although he’s joking, there is an element of truth to this. The hashtag is no longer simply a means of sorting – it’s become a multi-faceted, functional part of electronic language. It carries a specific tone, in the way that sarcasm does in spoken language.

And it’s trying to break free from its cage.

#Rise

The hashtag has nearly reached full integration online – so is it any surprise that it’s beginning to find life offline?

The biggest elephant in the room is will.i.am’s latest radio single, entitled “#ThatPower”. It’s an electronic, dubstep-influenced, build-up-then-break-down rave that features Justin Bieber on the hook – in a word, the song is relevant. By adding a hashtag to the song’s title, will.i.am has created a song that could only exist in 2013.

And this begs the big question: when we play “#ThatPower” for our children twenty years from now, will they laugh at it like we laughed at the bellbottom pants worn by everyone on The Brady Bunch? Will the hashtag as a functional language device become a part of history, like so many time-specific content words (see “groovy” or “bamboozle”)?

Or will the hashtag survive? Will it outlive Twitter and Facebook and become as linguistically important as pronouns and conjunctions? Will kids develop an intrinsic understanding of hashtags in the same way that they develop other language skills? Of course, it sounds crazy to suggest – but if you had told me in 1998 that I’d one day start putting the pound sign in front of particular words within sentences, I’d have called you #crazy, too.