I think the meaning is 'before lunch' and this is the sense of 'by' here. But you're right that 'by lunch' sounds just wrong in this case. 'by lunchtime' is a little better, but 'by' sounds too harsh since it implies the drinking of the lemonade must not continue into the lunch: 'Drink the lemonade by lunchtime or I'll send you to your room!'.
Actually, I think the intended meaning is "before lunch", not "during lunch". The possible translation of "by" would be more natural in the construction: "By lunch, we will be drinking lemonade", which means "we drink lemonade before lunch" in an awkward, but I think technically accurate, way.
"by lunch we will be drinking lemonade" isn't the same as "we drink the lemonade by lunch". The former suggests that by lunchtime you have started drinking lemonade, and you then continue drinking it during lunch. The latter means that by lunchtime you have finished drinking the lemonade.
This is a useful entry in the Word Reference dictionary
entro [ˈentro] prep within
entro un mese within a month
entro domani by tomorrow
entro febbraio by the end of February.
So does the sentence mean "we drink the lemonade by the end of lunch"? OR "we drink the lemonade before starting lunch"?
Actually, "by lunch" sounds perfectly good in spoken English... The intention is to finish drinking lemonade by the time you begin lunch... It's very similar to "I'll finish my work by lunch" or "I hope to get home by dinner"... In spoken English, you'd generally drop the "time" in "lunchtime" or "dinnertime" (which would then sound a bit weird) But contrary to what others have said, I don't think "We drink the lemonade by lunch" sounds weird at all...
In your example "finish work BY lunch", "get home BY lunch", etc- yes, the "by" sounds normal. But w/out some further explanation or context, to EAT or DRINK "by lunch" sounds weird, since lunch is WHEN you eat/drink. Now, if the sentence had been "Beve 3 birre entro pranza"....THAT would have made sense :)
"Beve tre birre entro pranzo" (Pranzo is a noun, you don't have to conjugate it)
"Beviamo la limonata entro pranzo" sounds a bit odd but it's not wrong
"Beviamo la limonata prima di pranzo" would sound more natural
"Entro" sounds like a deadline, if drinking something is a deadline... :D
A better example of using "entro" would be:
"Finiamo l'exame entro mezzogiorno."
We finish the exam BY noon.".
The Duolingo sentence is awkward and confusing.
When "entro" is used for "WITHIN" , it is usually referring to time or measure.
"entro l'anno" - within the year. "entro i due metri" - within two meters (of the target). Examples from Reverso Italian-English website.
Interesting question! Can we introduce a new subject/object subclause after a general preposition like 'entro'? Or would that only be allowed after 'che'? I would expect though that in this situation one would include 'io' too, to avoid ambiguity between the verb 'pranzare' and the noun 'il pranzo'.
Yes, but what I said was for this particular sentence. You cannot put a verb after entro, it doesn't work like 'before' in English. You should have a time expression or an event with a usual time (like lunch) after entro. I see what you mean, but it cannot be understood like that in this case (source: Italian girlfriend).
I wrote "Beviamo la limonata entro il pranzo" and was marked wrong, I guess because of the "il?"
I didn't think it was an error, so I went to report it but the usual option for "My answer should be marked as correct" wasn't there--leading me to think I was actually wrong.
Duolingo should find a better example to introduce "entro".
Nobody says something like this in Italy! A native speaker would think that this sentence has been invented by a stranger and would laugh, laugh, laugh...
Ex. Dobbiamo finire il progetto entro le due = We have to finish the project before two o'clock.
Then we can go to lunch and drink as much lemonade as you want, before, during or after
"by lunch" is planly and simply incorrect English here. I suspect that this is born of a necessity to "make" the translation fit the basic meaning of the Italian word, but prepositions cannot be simplified enough to work properly and consistently in this programme, with its digital limitations.
We drink lemonade "within" lunch was given to me as the correct answer and it is clearly wrong because it makes NO sense in English.
Reading the thread here it has become clear that Duolingo did not intend a meaning of "during lunch" Apparently that would be "durante" not "entro". So technically the English "We drink (the) lemonade by lunch" is correct but sounds clumsy and awkward in English.
I would suggest "We drink the lemonade before lunch" (the is now necessary not optional) or "We drink the lemonade by lunchtime" again 'the' is not optional. The meaning seems to be that the lemonade is all consumed before eating lunch. Not starting to drink it "by" lunchtime and definitely not "during" lunch.
So the remaining question is - is this sentence really correct in Italian?