Translation of downhill in German

My mom and dad used to speak English when they wanted to say something I shouldn't understand. In this way I have learned English. I did not tell them till late, but I did understand every word they said.
Usually we write these messages twice a week. We also have a fanpage in Spanish where we need to write short messages. It is actually pretty boring but people respond to it. Don't ask me why they are doing it.
Hi there again. I would love to visit you very much. I will keep that in mind for our next vacation... Your English is very good and I can't imaging that you have just learned it for two years.