'Each' with plural or singular verb
Is the use of have after each grammatical here?
Believe it or not, farther and further each have distinctly different meanings although people tend to use them interchangeably.
That is correct grammar. There are three forms of the word each:
In this case, each is an adverb meaning "apart" or "apiece". The word could be replaced with the adverb separately and it would carry a nearly identical meaning:
Therefore, the use of the verb form have is correct, since "farther and further" form the subject, which is plural.