"He does not eat apples."
Translation:Anh ấy không ăn táo.
"Anh ấy không ăn những trái táo." was accepted. What's the difference from:
Another correct solution: Anh ấy không ăn táo.
One of the corrections uses "trái táo". Is "trái" a classifier word? If so, is it for apples or for food in general?
Do you have to put the "trai" classifier in to use nhung? Why can't you just say "Anh ấy không ăn những táo" ?
I think you need it because once you express quantity by saying multiple you have to use the classifier as a counting word, like saying "multiple fruits of apple".
I'm not sure though!
you should use "không phải" only when using the verb "là" (to be) in the sense of being something. Like "I am not a man". but you won't use it if the sentence is something like "I am not happy".
Am I right by saying because the subject here is He therefore use "không" but if the subject is I then use "không phải là"?
No, it has nothing to do with the subject. "không phải là" is only used to negate the verb "to be" with a predicate nominative (a noun that identifies the subject). "I am not a man." or "He is not a student." https://www.duolingo.com/skill/vi/Negation/tips-and-notes