When to use "nor"?
NOTE: It literally means "and not." It expresses a negative condition and you are obligated to use "nor" if your sentence expresses a negative and follows it with another negative condition.
1. Let’s start with an easy one. When you use "neither" in a sentence, you use "nor" to express a second negative.
Example: Neither Mary nor Sam studied for the exams.
2. When there isn’t a "neither" in the sentence, you should still use "nor" if the second negative is a verb.
Example: That is not what I meant to say, nor should you interpret my statement as an admission of guilt.
3. However, if the second negative is a noun/adjective/adverb, you use "or". The first negative transfers to all conditions.
Example: Sam won’t eat cabbage or carrots.