I was raised speaking French Spanish and English, to this day I still think a bit in French... especially when spelling words... and sometimes, I can't figure out the English word and end up saying the French word...hehe
Living in Japan and learning Japanese, I have a tendency to always say "eto-o", and "kore, kore", and "arigato gozaimasu" all the time... so instead of saying "well...", or "ce chose si" I say the Japanese words. I rather enjoy thinking in other languages.