That's not QUITE true. German, like French and Italian, uses the tense that resembles our present perfect as the most common simple past. But if you are translating an English present perfect sentence into German, you must use the perfekt l. The Perfekt includes the perfect element where the Präteritum does not. Of course this is more obvious with very common nouns like haben and sein where the Präteritum is quite common. The less common à verb is, the more unusual it is to hear it in the Präteritum, so that distinction is less noticeable.