Translation:We are sightseeing in the city with a guide.
"Zwiedzamy miasto" probably translates to just plain "sightseeing." In English, we don't "sightsee a city." It is possible, though, to go "sightseeing in the city," or "sightseeing around town."
Both of the acceptable translations sound very awkward in English. I would never say I am sightseeing a city, nor would I say I am going sightseeing the city.
Yeah sightseeing is just not a transitive verb in English at least according to my gut sense. "...sightseeing in a city with a guide" sounds fine
Sightseeing is one of a class of English verbs that have two characteristics. First, they are intransitive because they already contain their object within the verb, and second, they always have an equivalent expression with the verb and object "unpacked". Other examples are: lovemaking, doorknocking, soothsaying, breakfasting, plus plenty of others. In each case, the verb doesn't take an object (lovemaking the bed would be bizarre), but it can be unpacked. So, one can say "they were breakfasting" or "they were breaking their fast". So, with sightseeing, the pattern is: they were sightseeing in the town, or they were seeing the sights in the town.
Is "przewodnik" a guide (person) or a guide (book)? The translate from word to picture at the beginning of the lesson showed a book, but it doesn't accept "guidebook" as a valid translation.
It is both, although I'd definitely expect the sentence to have a person in mind. But I wouldn't say that your version is wrong.
Hmmm, I tried to answer, "We are SEEING the city with a guide". Again, because as @va-diim already stated, we don't "sightsee a city"
My dictionary puts zwiedzać as being "To explore or visit", both of which sound much more natural in english than treating "sightsee" as a verb. We are exploring the city with a guidebook. You might in english also say, We are going sightseeing IN the city with a guidebook.
We are aware that this sentence is problematic to translate, but we have to teach it somehow, even if it means not necessarily sounding natural in English.
I don't think there's a problem in translation, if there is an exact equivalence of meaning. Rather that the English verb "sightsee" has to have "in the city" to be correct grammatically, rather than the exact Polish equivalent. If there's a lesson here, it's that sometimes between languages, it's impossible to get exact grammatical equivalence, but it is still possible to get exact equivalence of meaning. In this case if the Polish sentence describes someone going through the old town with a guide, and looking at the sights, then "sightseeing in the old town..." is the exact equivalent of the Polish.
Agreeing with some people above, I really don't think that "sightseeing the city" is a correct form ("in" is required). People from all sorts of language backgrounds speak English and so it may be emerging in some places as an acceptable form, but I don't think any English grammarian would say that it's correct yet.
Town is not accepted as a translation of miasto. Could this be added for learners from England? The centre of Krakow is the old town, for example.
The translation is grammatically incorrect in English. As mentioned above, 'sightsee' is an intransitive verb. It does not take an object. (My expertise: my degree is in English, and I get paid to write and edit in it.)
Please remove "sightseeing the city" as an acceptable translation. The default translation could be "sightseeing the city" or "seeing the city", both of which are grammatically correct.