In a charming old book "Russian Through Pictures" designed by Harvard University we have a picture of a mother and daughter preparing to enter a shop, and the text underneath says
Они войдут в магазин.
In the next picture we see them entering the shop and the text is
Они входят в магазин.
I thought I knew the difference between determinate/one direction (
Идти) and indeterminate/several directions (Ходить), but surely the determinacy of this action shouldn't change according to the tense?
So why the actual change here?
I suppose the preposition "в" explains the apparent paradox, but what is the exact rule?
In the books I consulted they explain at length the semantic differences between Идти and Ходить and conjugate them, but they don't conjugate these verbs with prepositions added.