My Deustsch, that's German in English, course, started last week. The trainer comes from Max Muller and is quite good. The training is evenly spaced and involves lot of practicals and revisions.
With any language, you have to unlearn part of the rules of the earlier language. English is closer in terms of script and the basic words, however, pronunciation varies hugely, Sometimes you are not able to deduce the meaning, only if you pronounce the word correctly. eg. ankreuzen (to cross) or tricken (to drink). And sometimes, the pronunciation misleads you. eg. Alphabet 'J' is 'ya' in German (and in other European languages as well). Hence it's Yapan.
However, a few things I like - alphabets are pronounced in the same manner always, unlike English where 'U' can create different sounds in put, but and mute.
Generally, it's great fun going to a class and learning the alphabet song and simple rhymes (in Deutsch of course) all over again.