I have bought two books but I haven't read [either - neither - both - all] of them.
Is both
choice correct? I know that either sounds more reasonable.
I have bought two books but I haven't read [either - neither - both - all] of them.
Is both
choice correct? I know that either sounds more reasonable.
The word which both makes best idiomatic sense and is grammatically accurate is "either".
"I haven't read neither of them" uses a double negative, and so is incorrect.
"I haven't read all of them" is incorrect because you don't use "all" when there are only two objects.
Now, "I haven't read both of them" is grammatically correct, but does not sound natural. Unless it is in answer to a specific question as to progress, and in that case, "both" would be emphasised. "I haven't read both of them yet, but I've finished one, and I've nearly finished the other one."
So it all depends on what you are trying to say.
If this is a multiple choice exam of which you are allowed to select only one option, then I would select "either", but it's a bad question.