Verbs and Correlative Conjunctions

Rules of Subject-Verb Agreement for Correlative Conjunctions

There are 5 correlative conjunctions:

• both . . . and
• either . . . or
• neither . . . nor
• not only . . . but also
• whether . . . or

For "both . . . and", the verb of the subjects will be plural just like 'and'.
For the rest 4 correlative conjunctions, the form of the verb will depend on the subject which is closest to the verb.

Both the students and the teacher are excited.
Both the students and the teacher are excited.

Either the students or the teacher is happy with the result.
Either the teacher or the students are happy with the result.

Neither they nor I am happy.
Neither you nor he is happy.

Not only the teacher but also the students are happy.
Not only the students but also the teacher is happy.

Let's see whether the students or the teacher wins.
Let's see whether the teacher or the students win.