You know you're a language nerd when…

[gsbod]

Your French homework requires you to translate a passage from English into French, so you also translate it into German, just to make sure you still can.

[Beli Tsar]

When you get stressed because you have been writting in different languages today and you continuously have to change the current IME (Input Method Editor) selection in your computer. (And you forget to do so beforehand, so you end up with a lot of gibberish written in the wrong language before you realize that and finally select the actual language you were trying to write in.

Or, someone else sits down to write something at your computer: they start typing and look at you in puzzlement.... And you say, 'oh, sorry that's Farsi, let me change the keyboard...', and in the process of trying to change to English you manage to cycle through three different scripts they don't understand...

[Olekander]

When you flick to a random romance language page and start reading about 15th century castles in Piedmontese, and then heading over to the history of Vespasian in Ligurian despite never having read or studied the language before cos you have a working understanding of 2 of the big 4 and some Latin.

[mentecuerpo]

When the only CD’s available on your glove compartment during that long family car trip are “drive time Italian and “rush hour French.”

[Cèid Donn]

When you don't feel you can't start your day without first doing some language stuff

When it's a cold morning and you make a cup of tea just to warm up your fingers so you can do some language stuff so you can feel your day has started properly

When you are grouchy towards the first human being to talk to you in the morning because they interrupted you mentally planning your language stuff for the rest of the day (as you sit in silence holding a cup of tea to warm your fingers)

When you resume your mental planning for the day only to get sidetracked by a "fond memory" of stalking a tourist family in a grocery store 15 years ago because you were so excited that you could actually understand about 20% of what they were saying to one another in their native language

[PfifltriggPi]

... You're speaking Ukrainian in your Modern Greek class.
... You're annoyed at how all other students in your French lit class keep talking while awaiting the arrival of the teacher, since you're trying to read Latin.
... You repeatedly and fruitlessly try to speak Latin with the other students in your Latin class.
... You pass up lunch to go to an Italian conversation group.
... You speak Ukrainian during your French conversation group.
... You know songs in at least 5 languages off the top of your head.

[golyplot]

You get excited when you think you hear parents speaking Dutch on Halloween, only to discover that it's just German instead.

[Teango]

When you're on a quiet articulated bus in Honolulu when two dozen Filipinos and Filipinas get on, chatting loudly and passionately in pairs and small groups of all ages. The hubbub of Tagalog is as deafening as an Irish bar on a Friday night, and several other passengers start to grumble to each other and glance menacingly back towards the second half of the bus; some even alight at the next stop to catch another bus. I...however...am in seventh heaven!! I kid you not, I can't remember the last time I felt this pleasantly chilled out. I actually stood up, gave up my comfy seat to another passenger, and shuffled right to the back of the bus to be in the thick of it. I eventually managed to squish myself next to two animated women discussing a famous actor (as far as I could figure out) and let the music of the language flow over me. Smiling inanely to myself out of pure language nerd contentment, my head gently tipped back and forth and swivelled periodically from side to side to pick out snippets of different conversations. And if I hadn't been picking up my daughter from daycare at the time, I'd have definitely and deliberately missed my stop.

[Bluepaint]

When you go on holiday for a month but spend a fortnight of it taking language classes

Edit: this isn't even my nerdery, it's that of another member and I was struck by just how perfect it was for this thread

[Deinonysus]

When you have to stop playing your brand new Star Wars game because you recognize that some rock music playing in the intro is by The Hu, and you need to go read about Mongolian.