One of the hardest things about learning a language for me is getting the old ones out of my head. It took me forever to stop speaking Arabic when we went to Kyrgyzstan the first time, and when we were there the second time Russian kept coming out even though I was hearing Uzbek and Kyrgyz all the time and trying to speak in Kyrgyz myself.
Russian is still coming out now even though I'm supposed to be speaking Spanish. I understand quite a bit of Spanish and can read it fairly well, and I can say it in my brain, but I cannot get Spanish to come out of my mouth. It's always Russian. But I managed to speak Arabic, and Russian, and even some Uzbek, so I think that Spanish will make an appearance someday.
I wish there were some way to switch language modes more easily. I suppose I just ought to learn each language better. And I sincerely hope that the next country we live in will use something I've already learned.