The German dictionary I usually use has a pretty long list of words that are all translated into English as »towards«:
- zu, which, if so, seems to be indistinguishable from »to«
- auf jmdn. / etw. zu
- gegen
- nach
- in Richtung
- gen
My question to you is, are all these words for »towards« interchangeable, or has each of them developed a specialized meaning that can only be used in certain fixed contexts? No dictionary or grammar, for that matter, makes this clear.