"We are strolling in the forest."
Translation:Мы гуляем в лесу.
No, it won't. A limited number of nouns has 2 prepositional case: normal prepositional case used after «о», and second prepositional case (also called locative) used after «в», «на», «по» which usually looks like Dative for masculine nouns.
Sorry, I don't understand your question. You say stress changes from «е» to «у», but why should it be on «у»? Stress in all the singular forms of «лес» is on the first syllable of the word.
- If this is a question about stress placement in «лес», then there are no real rules for stress in Russian words. There's Zaliznyak's article, but it's so technical and so long that it's easier to learn stress with each word.
- If this is a question about shifting the stress to preposition, «по́ лесу», then I think stress can shift to the preposition only if it's normally on the first syllable of the word; and such stress shifts are generally optional (so both по ле́су and по́ лесу are correct).
- If you're asking why we say «по лесу» and not «по ле́се», it's because «по» is used with Dative. (Edit: I've edited this sentence because it was incorrect before.)
Oh, I see! Perhaps it's a regional difference, then.
I've never heard «по лесу́» here in Belarus, but I guess it's different in different places.
I doubt a native speaker would say «мы гуля́ем в лес». Гуля́ть has a shade of meaning 'to move without a clearly set direction'. Even though we usually have some route in mind when we go гуля́ть, the meaning of this word implies we can change the direction anytime because it's not really determined.
That's why «в лес» doesn't work well with this verb: «в лес» suggests we have a fixed destination, and «гуля́ть» means we don't have it.
«В» has different meanings depending on the case of the noun:
- в + prepositional case describes location and is translated 'in': «я живу́ в Ви́тебске» 'I live in Vitebsk', «я гуля́ю в па́рке» 'I walk in the park' (if the noun has a separate locative form, use it instead of the normal prepositional case form: «в лесу», not «в лесе»),
- в + accusative case describes destination and is translated 'to, in, into': «я прие́хал в Лиссабо́н» 'I came to Lisbon', «я иду́ в теа́тр» 'I'm going to the theatre'.
In non-emphatic sentences, Russian places the known information in the beginning, and the new information in the end. So, here's the explanation of your sentences:
- «Мы гуляем в лесу» is a sentence answering the question "What do you do?". Мы is a known information (the listener expects the sentence about 'us'), «гуляем в лесу» is the new information (we tell what we're exactly doing).
- «В лесу мы гуляем» is a sentence answering the question "What do you do in the forest?". «В лесу» is a known piece information (the listener expects a sentence about the forest and about us), «мы» is also a known piece of information, and «гуляем» is the main piece of new information: we tell that we walk there (we don't work there, we don't pick up berries or mushroms, we just walk).
- «Мы в лесу гуляем» means roughly the same thing, but it's a more sentence about "us". I.e. if the previous was likely to be used to describe what people do in the forest (not neccessary what we do), this one is likely to describe what we do (not neccessary in the forest).
- «В лесу гуляем мы» is a sentence answering the question "Who does something in the forest?", "Who is in the forest?". «В лесу» is a known information (the listener expects a sentence about the forest), and the new information is that it's we there (it's not Ira who's walking there, it's us).
- «Гуляем в лесу мы» is a sentence answering the question "Who strolls in the forest?". I.e. the listener knows who goes to the forest to pick up mushrooms, but she doesn't know who goes there just for a walk, and we say: actually, we do. «Гуляем» is the main piece of the known information, «в лесу» is also a known information, and «мы» is the new information. This is more a sentence about walking than about a forest: 'we' walk in the forest, and someone else picks berries there.
- «В лесу гуляем мы» means roughly the same thing, but it's more a sentence about a forest and not about walking: we walk in the forest, and someone else walks in the steppe.
- «Гуля́ем мы в лесу́». Here, «гуля́ем» is the known information, and «в лесу́» is a new information. Such word order is often used to introduce a new situation as a background, because the new information here is «мы» and «в лесу́». Even in «гуля́ем» is not known by the listener (it's the beginning of the story, after all, listeners knows nothing!), placing it in the beginning marks it as something unimportant, already known. The important parts are placed near the end of the sentence: «мы» and «в лесу́». So, this sets a background for the following story that will be about us and that will happen in the forest (it doesn't matter much that we were walking before the story happened).
If you have no previous context, «Мы гуляем в лесу» is your best bet at translating "We are strolling in the forest", because this is the most common word order.
Hope that helps!