"You see, the preposition thing is complicated. Do you think that your students must solve the problem in detail? In my opinion they may make mistakes. People understand them surely!" Mrs Engelhardt has asked me this question while she explained to me about prepositions which I asked.
We, Indonesians, who learn German, have sometimes difficulties in choosing the right preposition as we should build a sentence. It is possible that an Indonesian word (not always a preposition) can be "represented" by more than one German preposition. For example: the word "melewati" in the sentence "Anak-anak melewati taman." For the word "melewati" these prepositions are possible: "durch", "ueber", "an...vorbei" because these prepositions can mean "melewati" in Indonesian language.
Now we try to build German sentences from the above-mentioned example. Anak-anak means Kinder (= children) in German, taman can mean Park or Garten (park / garden).
So:
1. Die Kinder gehen durch den Park.
2. Die Kinder gehen ueber den Park.
3. Die Kinder gehen am Park vorbei.