Are "noth both" and "neither nor" equivalent?

lsatsuperstar

Q7 here:
https://7sage.com/lesson/inout-game-1-questions-part-1/

Are "noth both" and "neither nor" equivalent?

LindseyDC

neither nor = not this and not that, so yes. it essentially means "not both".

Jonathan Wang

Actually, no. Take, for example:

I don't have both a brother and a sister

versus

I have neither a brother nor a sister

The first says you don't have both. You can have just a brother, or just a sister, or maybe even no siblings. You just can't have both a brother and a sister.

The second specifically states you have 0 brothers and 0 sisters - so the only possibility is no siblings at all.

There is overlap between the two concepts ("neither"), but they are not identical.

Put in more formal logic, neither nor is specifically "not A and not B", while "not both" is "not A or not B", which leaves open the possibility of "not A and not B" but does not require it.