"The merchants carry the food and sell it in the forum."
Translation:Mercatores cibos portant et in foro vendunt.
It is acceptable mediaeval Latin as it is. The pronoun “illum” by then does not always just mean “that”, but “eum” (“it”) might be more usual (“...et eum in foro vendunt”). The “correct” sentence is still not particularly good Classical Latin because two main clauses are combined by “et”, rather than subordinating one to the other.
That would make the first verb the main one, and is of course quite possible: mercatores cibum portant ut in foro vendant. If they are already selling it, however, it is the carrying which needs to be subordinated: mercatores cibum in forum portatum vendunt (Merchants sell food having been carried into the forum - it’s clear that they are selling the food in the forum since that is where they carried it to).
You should be confused by that! The suggested answer is wrong, since the plural eos does not agree in number with the singular cibum.
I also wrote "Mercatores cibum portant et in foro illum vendunt.". They frequently give sentences with unnecessary words as "correct" alternatives, so I'm not sure that "illum" is the problem. Maybe it's another case of our needing to be able to guess when they're using a word like "food" or "fish" as a plural versus a singular noun. Hard to learn from mistakes when you don't know what was wrong and why.
No, because your English sentence means that they must carry several kind of food, and it's not mentioned in the Latin sentence.
I believe, according to the examples I saw, that both the singular and the plural is used to mean food, as you would have la nourriture/les aliments, a singular and a plural, in French to mean food. And it's also very plausible that the plural mean "meals", but never "different kind of foods".
To mention several kind of foods, it would be another way in Latin, as "food" is not an uncountable in Latin, the specificity of uncountable nouns don't apply to it.
It's very common in Latin to establish an object and then have multiple verbs apply to it, where in English we would tend to keep referring back to that object using pronouns.
Exempli gratia, "they arrested him and put him in gaol" would very naturally be expressed in Latin with only one "him": "eum comprenderunt et in vincula coniecerunt".
Firstly, 'cibos' plural can be used, but is not the literal translation of 'food' singular. Secondly, the sentence could be 'Mercatores cibos ferunt et eos in foro vendunt'. But if you'd be doing those small corrections, you could go on and on, especially with sentences about killing (for which latin has a lot of verbs and expressions)
Nunc omnibus qui lingua anglica non valent tam lingua latina: sententia haec revera deberet esse (Anglice): The merchants carry the [foods], nam si 'cibos' obtinere velis a studiosis, [food] non valet. Id enim transtulitur 'cibum' (acc. masc.).
I've found expressions where "cibos" plural refers to "food". (but never "foods")
"cibos" in my opinion, mean meals/dishes, and sometimes food (depending of the context)
admitto aliquid in cibos= I use a substance as food (yes, you can also say "meals" here, the difference is weak in this context).
cibos libo = I taste dishes.
In Classical literature the singular is about twice as frequent as the plural. If there is any significant distinction, I would say that the singular is food in general or just “some food", while the plural would signify “foods”, “dishes", types of food, etc., and sometimes possibly all types of food, thus making it universal.
Does "food" need to agree in number with the subject of the sentence?
No, it doesn't.
So why in this sentence, "Mercatores cibos portant et in foro vendunt.", is "food" plural?
You can also use the singular "cibum"; I'm sure that is also accepted. Other comments on this page have noted that the plural could refer to multiple meals, or multiple types of food, either of which could also be described as simply "food."