While speaking or writing, do you sometimes use words or phrases from other languages as substitutes for the ones in the language you are mostly using?

Moi?
NEIN!

Occasionally, since I'm bilingual in English and Spanish and do pretty well in French. But I only do it with people who know me really well--otherwise I would come off as a total puff-head.

Hare Krishna!

Yes, I do it tout le temps.

I do only when I'm around someone who speaks the same language.

Oh yeah, a lot of foreign phrases have come into regular English usage like that. I pop up with more obscure ones from time to time. I'll often say "c'est moi" when I knock on someone's door, or buzz their apartment. Or "Shall we frappe la rue?" I'm pretty sure I use Latin and German occasionally, but it escapes me...

I do it when speaking, but not so much when I'm writing. Probably because I'm not sure how to spell some of the words I use!

Of course!

Yes. English, French, Latin and German.

I frequently find that a well-chosen foreign word or phrase will add that certain je ne sais quoi to my writing.

(ROFL) You have no idea how often that happens with me. Not intentionally, but sometimes I just can't remember the word I want to use in the language I am speaking (including my native language). So I use the foreign word or phrase. If my listener is bi-lingual, I just keep plugging away knowing that he/she will know what I meant.

I remember one time in Mexico when my wife and I started a discussion in English, slipped into Portuguese and ended in Spanish. Curse words included.

So rarely that I answered no.

Yes, although English adopts words from other languages so readily that many of these phrases could almost be considered English.

Sometimes I say adios for the heck of it.

Nope

All the time if I'm speaking french. And probably next year when I take spanish. When I count in french, I always switch over to spanish counting also. Just in everyday life, I sometimes say andiamo (that's not how you spell it) which I think means hurry up.

sometimes

I speak in Japanese and say "uber" far too often for my own good.

yups...especially since ive been taking spanish since i was in kindergarden...i throw some english words in spanish :)

I don't speak French, but I find myself using French phrases in my normal conversation because they just seem more accurate in expressing a feeling. Terms like: avante-garde, joie de vivre, pièce de résistance, carte blanche, dénouement, raison d'être, de rigueur, ennui, tour de force, and faux pas...these are just a few I use on a regular basis. The English translation just doesn't seem to say all that I mean. I guess I rely on them as "meaning shorthand".

only when i'm joking around with people. I'll say hello and good bye in spanish but that's it.

French, mainly.

sometimes. I use danke or merci instead of thankyou. Or boka instead of bye.

Yes. Those things make you look smarter (of course, if you use them properly).

when I speak a second language and don't know a word, I substitute an English word