1. Use each of your languages to accomplish a task every day. This doesn’t mean that you need to have a half-hour Skype session every day to keep on top of your languages. What it does mean is that you should use each language to accomplish a task of so

Speak with native speakers. If you don't speak the language, you are unlikely to learn it well and keep it in your memory. There are programs that link people learning a language and native speakers via Skype. If you can't do that, look around you