I know the basic idea of "one" and "it". "One" means "a..." and "it" means "the...". How about the sentence below? Which word would you choose?
- My son is allergic to nuts. He gets sick when he eats (one/ ones/ it/ them).
To my understanding, the correct choice is either "one" or "ones" because the sentence is not talking about particular nuts.
(The son becomes sick when he eats a nut or nuts, not the nut or the nuts.)
However, the English lesson material below says "He gets sick when he eats them."
https://eikaiwa.weblio.jp/information/travel-english/about-allergies
Why is "them" used here although the sentence is not talking about particular nuts? Since this is not about particular nuts, I guess we should use "ones" here instead of "them", which corresponds to "the nuts".
Is my understanding incorrect? Why is "them" used here though it's not about particular nuts?