Directionality of prefixed verbs of motion in present and future

Question

From duolingo.com

A TRICKY ASPECT

You may have spotted so far that the examples have all been the one-directional versions of 'go' and that they are all past or future. Well, here's where it may get confusing. When they have a prefix attached, the one- and two- directional versions of 'go' convey aspect rather than 'directionality'. This probably makes more sense with an example:

Я перехожу мост - I am crossing the bridge/I cross the bridge

Я перейду мост - I will cross the bridge.

I read this and other answers already, but I am quite uncertain.

How would one differentiate then between e. g.

• Tomorrow I will go to Dima and I will cross this bridge. and
• Next month I start to go to school and en route I will cross this bridge.?

By context and signal words?

Does it mean somehow there is no directionality for prefixed words in present and future?

Answer 1

Russian verbs are not to be divided into "prefixed" and "unprefixed", but rather into perfective and imperfective.

Переходить is imperfective, which means it has "normal" present tense: Я перехожу мост = I cross / I am crossing the bridge. (But it has both past and future tense too: "Я переходил" and "Я буду переходить").

But Перейти is perfective, which effectively means that corresponding action is thought to be finished at some moment. Thus Я перейду мост translates into future tense I will cross the bridge. (It also has past tense "Я перешёл", but no present tense at all).

But note that in English "I will cross the bridge" may mean different things, because it's an indefinite tense. You may think either "Tomorrow I will cross that bridge, and then I will go to some other place" or "I will cross that bridge once in a day from now on" etc. In Russian you have to use different verbs, as there's no such thing like "indefinite" tense.

So the point is: in Russian you must think of "perfective / imperfective" actions first, and of past/present/future afterwards. All "continuous tense" belongs to imperfective; all "perfect tense" belongs to perfective; "simple tense" is 50/50 depending on what you really mean.

In your examples the first one is certainly perfective (you're going to have some action be done once), and the second one is imperfective (you're going to repeat some action many times). This is what makes the difference. You need no additional signal words in Russian, as you have to choose the proper verb to say what you want to say.

Я пойду / Я перейду vs. Я начну (буду) ходить / Я буду переходить.

Answer 2

I believe what Duolingo is trying to tell you, not very effectively, is that unprefixed verbs of motion have two imperfectives: (1) the so-called iterative (2) and the multidirectional. Aside from these, there is also a perfective with prefixed по-. So in the case of going (on foot), these would be идти impf, ходить impf, and пойти perf, respectively.

However, once a prefix is added, the verbs of motion go back to being like all other verbs - one perfective form: перейти, and one imperfective form: переходить, responding to the same aspectual dictates of any other verb.

Answer 3

Not sure what your question is, but first will be translated as: "Завтра я пойду к Диме и перейду этот мост" and second one as: "В следующем месяце я начну ходить в школу и по дороге буду переходить этот мост"

Btw "Завтра я пойду к Диме и перейду этот мост" - sounds quite hmm... bizarre.