"One (simple perfect = Imperfekt) is for the written form, the other (present perfect = Perfekt) is for the spoken form" is an oversimplification. Both German and English (and most other European languages) have the same tenses, so you can translate them literally. But tenses are used differently in German compared to English. Depending on the situation, you'd choose one or the other in German, and that has no relation to what tense you'd choose in English. So it makes no sense to ask "how would I translate this form into English", it's rather "what tense is appropriate in this situation". Both in spoken and written German, Perfekt and Imperfekt are more or less exchangeable. In many situations, you can use either. In this case, Perfekt has the nuance of being a bit "less formal", so in spoken German, it is preferred. For the same reason, Imperfekt is often preferred in written German to appear more "serious". That is where the classification you have heard about comes from. But there are situations where they are not exchangeable and you can use only on. 1) In a narrative text that tells a story, you always use Imperfekt. 2) Perfekt is for situations where the action is completed and has stopped. This is especially the case in temporal subclauses with e.g. "nachdem". Imperfekt in these situations would be wrong, both in written and spoken German. 3) Imperfekt is for situations where the action is still ongoing or was ongoing for a long time. To use Perfekt in those situations would imply that the action has stopped, so that would be wrong both in written and spoken German. Also see: http://www.italki.com/answers/question/135554.htm http://www.italki.com/answers/question/56589.htm

Translating literally is never a good approach, so you are right: The difference between the 2 ways of past tense is exactly here: spoken or written (apart from the modal verbs, haben and sein). Since in English this kind of difference does not exist, one cannot translate it, but must pay attention to how it is used in the other language.