I sort of see your point. You're right about verbs though. I have trouble with the prefixed vowels. Like for ich abpfeife. Is it Ich pfeife ab, or how about ich habe die Pfeife abgepfeifen.Abgepfiffen
. (Not that that sentence makes much sense in any case.)
There are several clues to getting these right. First of all, not all prefixes can go either way. Some, like be-
, and ver-
, are always inseparable. I hesitate to say that there are also ones which are always separable, but if there's a verb with, e.g., inseparable prefixed ab-
, then I don't think I've ever come across it. (Note, however, cases like verabschieden
, where an inseparable prefix is added to a verbal noun, i.e. Abschied
, derived from a verb with a separable prefix, i.e. abscheiden
. They look an awful lot like verbs with compound separable prefixes, e.g. herabsetzen
, but behave completely differently.)
Second, where there's a contrast, the inseparable prefix generally has a meaning that is less literal and more abstract. For instance, übersetzt
(insep.) means "translated" where as übergesetzt
means "ferried across a river" (that is, literally "set over").
Third, the stress is different. Uebersetzen
has primary stress on the stem when inseparable; when separable, both the prefix and the stem get equal stress.