Collective plurals should also be accepted. “Tomatoes are not vegetables” would sound more natural in English.
In the sentence I gave above, the word “tomatoes” is a collective noun. This means it represents a singular concept. In English, we might say, “A tomato is not a vegetable,” but it is more likely we would say, “tomatoes are not vegetables.” We would not say, “Tomato is not a vegetable” unless Tomato happened to be the name of our cat and we wanted to express that Tomato was indeed not a vegetable.
You are overthinking. Hindi is different from English. The idea is in the sentence the words सब्ज़ी and है are singular. There are other sentences where plural is used. It's basically getting you used to the differences in them.
If you feel the translation is in error, report it. But, this particular sentence is singular. Some may say "a tomato is not a vegetable". I think that's what you are missing. The word "a" is not necessary in Hindi.
It’s good to know that the indefinite article is not necessary in Hindi; however, it is necessary in English and it has been left off here.
It's not really necessary in this sentence. It just sounds funny to you, because we normally do use it. Grammatically, there's nothing wrong with the sentence.
I think this is one of those cases where the sentence does sound natural in Indian English, but does not in American English. In American English or would be far more typical to say "Tomatoes are not vegetables." Both ways should be accepted as correct answers.
Agreed. I put that and was marked wrong, but I agree that in a normal conversation, most would say "Tomatoes are not vegetables" as opposed to "Tomato is not a vegetable".