So, lad—you're getting your sight straight in your first days topside, so here's some advice: you're not just trading with kin. You're selling to all kinds of folk now, with different customs and tongues. As I've learned here, the most important part of any language is the cussing. It gets you trust. It gets you coin.
Most elves you see in the city are servants, and a human looking for a fight might call one "knife-ear." If the elf returns with "shem" or "quick," blood's about to spill. Those Dalish elves use "flat-ear" to insult the ones who live with humans—like our unenlightened kin below calling us Stone-blind up here.
Even the humans who pray to some woman they burned alive—and her god they call "the Maker"—say something when they knock their shins. It's a curse to say "Andraste's..."—well, any body part, really. "Maker's breath!" might get you in with a swaggering fool, but the lady priests won't be pleased. Chantry folk also don't like mages. If you hear a mage called a "spellbind," hide anything flammable.
Then there are all those beautiful words that just mean "Sod it!" When that loose cobblestone flips and the ankle cracks, an elf will cry, "Fenedhis!" while a human might, "Damn it!" A Qunari will mumble, "Vashedan!" I've even heard a couple Tevinters yell, "Kaffar!"
If any of these get aimed at you, hopefully all that gets killed is a sale.