Quidquid latine dictum sit, altum sonatur.
(Whatever is said in Latin sounds profound.)
With that in mind, then, here are some very usefully impressive phrases with which you may pepper your speech - ten million points if you actually manage to casually drop one into conversation:
Vah! Denuone latine loquebar? Me ineptum. Interdum modo elabitur.
Oh! Was I speaking Latin again? Silly me. Sometimes it just sort of slips out.
Sona si Latine loqueris.
Honk if you speak Latin.
Si Hoc Legere Scis Nimium Eruditionis Habes
If you can read this you’re over-educated
Mihi ignosce. Cum homine de cane debeo congredi.
Excuse me. I’ve got to see a man about a dog.
Noli me vocare, ego te vocabo.
Don’t call me, I’ll call you.
Te precor dulcissime supplex!
Pretty please with a cherry on top!
Mellita, domi adsum.
Honey, I’m home.
Te audire no possum. Musa sapientum fixa est in aure.
I can’t hear you. I have a banana in my ear.
Catapultam habeo. Nisi pecuniam omnem mihi dabis, ad caput tuum saxum immane mittam.
I have a catapult. Give me all the money, or I will fling an enormous rock at your head.
Re vera, cara mea, mea nil refert.
Frankly my dear, I don’t give a damn.
Ita erat quando hic adveni.
It was that way when I got here.
Illiud Latine dici non potest.
You can’t say that in Latin.
Nescio quid dicas.
I don’t know what you’re talking about.
Non sum pisces
I am not a fish
Cogito ergo doleo
I think, therefore I am depressed
Quid agis, medice?
What’s up, Doc?
Certe, toto, sentio nos in kansate non iam adesse
You know, Toto, I have a feeling we’re not in Kansas anymore
Me transmitte sursum, caledoni
Beam me up, Scotty
Sentio aliquos togatos contra me conspirare.
I think some people in togas are plotting against me.
Quantum materiae materietur marmota monax si marmota monax materiam possit materiari?
How much wood would a woodchuck chuck if a woodchuck could chuck wood?
Braccae illae virides cum subucula rosea et tunica Caledonia-quam elenganter concinnatur!
Those green pants go so well with that pink shirt and the plaid jacket!
Sic hoc adfixum in obice legere potes, et liberaliter educatus et nimis propinquus ades.
If you can read this bumper sticker, you are both very well educated, and much too close
Utinam barbari spatium proprium tuum invadant!
May barbarians invade your personal space!
Vescere bracis meis.
Eat my shorts.