The verb to be can be one of the trickiest and most irregular in the English language. Its forms change drastically depending on the tense. Even native speakers can bastardize it over the decades to the point that technically incorrect phrasing has crossed over into common usage and understanding (though, in fairness, this is the case with many verbs).
So, when to use is and are? Applying the verb to different subjects and objects might cause confusion, especially when referring to a plurality. Here is a guide to help you determine whether to use are or is.
Generally, is refers to a singular subject and are refers to a plural one. The question of is vs. are really comes to the fore when the subject is not definitively singular or plural.
This is why different English-speaking regions have their own approaches to collective nouns: Americans say “my family is happy,” for instance, whereas Brits opt for “my family are happy.”
Of course, where an actual plural is concerned, are is almost always the proper verb.
We are both going to miss our families.
Whether you or I are driving, we’ll have to leave early.
I don’t believe they are from around here.
Whenever there is a choice or a space that excludes something — either this or that, neither this nor that, none of these things — is fits the bill more often than not.
Some people find this arrangement unnatural, but think of the fact that “none” is a contraction for “not one.” You would say “not one is,” not “not one are.” Try it out and see how quickly you adjust to it.
Nothing is as it seems.
Either he or she is about to be in very big trouble.
She showed me the flower arrangements, and none of them is very pretty if you ask me.