You say language and people think of words. But what you really mean is everything that language encompasses, including tone, gestures, facial expressions, implications. Look at that, we’ve said one word and we’re already miscommunicating.
We certainly rely heavily on non-textual cues to convey meaning. You could text me “My Grandma is making me dinner” and I would think nothing of it. But you stand in front of me with sweat beading on your forehead and terror in your eyes and say “My Grandma is making me dinner” and I’d be like “Dude, why didn’t you ever tell me your grandmother is a cannibal?”
We need specific words to convey specific ideas. But without the enforcement of non-verbal cues, communication breaks down. One guy says, “Hey, Bro, like your tie.” But his eyes say “Hey, Bro, like your tie, lets have sex in the copy room again.”
It’s the same with symbols. People use symbols all the time to convey meanings without the use of words. You see a white building with a cross on top, you think church. But you go in to offer your praises, maybe light a candle, gossip about your neighbors bad spray tan, and instead of finding a room filed with pews you find goats grazing over a carpet of indoor grass. Then a guy in a white tunic says to you “This is no church. In my country cross is symbol for goat farm. Is very unfortunate coincidence.” And that’s fair, because every culture is different. But, at least 99% of the time, building with cross means church, and no words are needed to express that.
Of course even those shades of gray aren’t always black and white. As we know this type of communication occurs, we frequently misinterpret would-be symbols all the time. I see a guy walking down the street in an expensive, three-piece and I think. “That guy makes a ton of money.” Where in reality he’s a hobo with a meth problem who steals people’s clothing while they’re getting CAT scans.
Frequently there are errors as well. In a world of emoticons, you may be trying to send a happy face to someone to convey, you know, happiness. But what happens when you press the wrong button and you send them an image of a cat eating a donut? What, exactly, does that convey? It may express happiness if, coincidentally, you had already been talking about how much you love cats and/or donuts. Other than that, you’ve most likely rendered the other party brain dead in an attempt to interpret what was really just folly.
The point is, communication relies on a conglomeration of words, expressions, tones, gestures, and symbols to convey meaning. But, in the end, it’s likely no one will understand what you’re trying to say anyway.