Russian Language/Russian preposition NA vs. B
I have been teaching myself Russian for around 4 months now and have come across a question recently involving these prepositions.
Мы идём иа стадои
мы идём в парк
Both mean "we are going to or we go to" but I don't understand why one uses NA and the other uses B
First, semantics. In case of a park, you go 'into' the park if you are Russian. Not exactly 'to' the park since to the park would be 'к парку' like 'unto' the park. Again, this is when you think in Russian.
When you go to a stadium, you go 'onto' (на) because you don't go inside of it like indoors. Unlike the park being a 3D object with trees over your head. While the stadium is 2D flat.
You may say 'в стадион' meaning entering the premises, buildings, and infrastructure, not the field. That would sound weird but that's what the meaning would be.
So hopefully, you did get the idea that 'B' means going inside of a 3D object while "HA" is going to something 2D and flat that you are stepping on.
Of course, there are examples where semantics are not as apparent as with the park with trees over you and the stadium as a ground you walk over.
There are words like territory which can have both prepositions. Still, the difference would be about 2D and 3D. 'Входить на территорию' would be walking over it. 'Входить в территорию' would have a sense of watching from above like to the map, without the feeling of walking over the ground.
Of course, one needs to memorize phrases and 'lean not on your own understanding'. While writing this, I realized for the first time that 'in' and 'inside' in English may refer to flat objects. I used the prepositions as I heard them used but didn't consider the difference with Russian.