[Source:] It’s also worth noting that the corrected version doesn’t use but, but but then. The then is a key word that makes the sentence sensible; it indicates when Joey realized his wallet was at home – after they had reached the head of the line. Without that word, neither but nor yet make apt conjunction.
1. The correlative conjunction ‘neither … nor’ is singular, and but and yet here are singular subjects, so should make be makeS?
2. apt conjunction as the predicate looks wrong, but I can’t pinpoint why. Should this be an apt conjunction or apt conjunctionS ? Why or why not?
Yes, you’re correct. The same rule that applies to either…or or simply or also applies to neither…nor. If the subjects are singular, the verb that follows them should also be singular: Without that word, neither but nor yet makes an apt conjunction. Note that in the case of mixed subjects (i.e. one singular and one plural) the verb will match the subject that is closer to it.
Based on the singular subjects, it should be written as an apt conjunction.
Source : Link , Question Author : NNOX Apps , Answer Author : pyobum