Memorize these basic rules:

1. Phrases or words separated by and are plural;
2. Phrases separated by or or nor are singular.

In this example, we see a list of three names. Because these names – Ted, John, I - are separated by the word "and", the plural form of the verb is used, according to the rule stated above. Don't over-think this one. It's an extremely straightforward grammatical construction: the subject is plural because it refers to more than one person (or place, or thing, or event), and plural subjects require plural verbs.

In this example, we see another list, of two names. But this time the verb is singular, not plural. Why? Because the names are separated by the word "nor." And according to the rule above, when a list of things is separated by the word "nor," the singular form of the verb is used.

This construction is, as you can probably tell, the more complicated of the two. At first glance, it looks very much like the “and” construction (though the meaning is the opposite). But, in fact, the two constructions are rather different. In the first sentence, three people are going. In the second sentence, neither one of two individuals, Ted and John, is going. Since, in the second sentence, the two people are referred to individually, as separate entities, it wouldn't make sense to use a verb that refers to them as one unit.

The way the second sentence is constructed is rather like using the term "no one." Would you say, no one are going? Or, no one is going? You'd say the latter. How could "no one" be plural? Do the same with "nor" and "or" constructions.

Here are some more words whose grammatical numbers (singular or plural) are commonly confused.

A. Pronouns

	A. The following pronouns are always singular: anyone everything something anybody whatever no one anything whoever/whomever nobody everyone someone nothing everybody somebody

Many of the words in this category can be broken down in a way that illustrates their essentially singular nature:

	B. The following pronouns are always plural: both many several few others

Memorize these.

	C. The following indefinite pronouns could be either singular or plural depending on context: some none most any all

''Depending on context" means that, for the pronouns in this list, you can't depend on memorization. Look at these examples:

Some of the bananas are brown.

Some of the banana is brown.

Both sentences are correct. Why does the first require a plural verb, and the second a singular? Because, in the first sentence, some refers to several distinct objects:

If we have, say, ten bananas, then some of the bananas means either two bananas, or three bananas, or four or five or six – in any case, many individual bananas. But in the second sentence, some refers to part of one object:

One part of one banana is brown. In this sentence, some means "part" – which is singular.

This trick works for the words some, all, any, and most. For any, the verb will usually appear before the noun, but the same principle applies: if any is followed by a singular noun, use a singular verb; if it's followed by a plural noun, use a plural verb.

It's exactly the same concept: the direction ( the arrow in these diagrams) is just reversed. The trick applies equally well for some, all, any, and most.

The pronoun none follows slightly different rules. Look at these sentences:

None of the ice cream was left over.

None of my friends are going to a play tonight.

None of the inmates was given a fair trial.

See something strange? The first and second sentences look fine, with a singular noun followed by a singular verb and a plural noun followed by a plural verb. But the third sentence contains a plural noun and a singular verb. How could this be?

Unlike agreement for the pronouns all or some, agreement for none isn't always determined by the noun following it. The word none can be used to mean either "not any" or "not one", and sometimes, only context, or the writer's intended emphasis, can determine which use is better. Fortunately, however, in most cases – probably all cases on the GMAT - its meaning in the sentence, and the verb it requires, can be derived the same way it is for the other pronouns: by referring to the noun immediately following it. If the noun is plural, the verb is plural as well; if the noun is singular, the verb is singular. Let's look again at the first two sentences:

The noun following none — ice cream— is singular, and so the verb should be singular as well. It is also helpful to note that none is most often singular when it means no part of – as in, none of the ice cream, or none of the chicken, or none of the baseball field.

None of the ice cream was left over

can become

None of it was left over

Here's a case in which none is plural:

Again, fairly straightforward: the noun following none is plural, so the verb is plural as well. When plural, none means "not any":

Not any of my friends are going to a play tonight.

The alternative is for none to mean "not one," which carries essentially the same emphasis as "not a single one." So unless the friends attend a play every night, there's no reason to say that not a single one of my friends is going.

The second sentence, however, does require such emphasis:

None of the inmates was given a fair trial.

When you come across a confusing sentence like this, in which the noun is plural, but you're not sure whether the verb should be too, ask yourself this question: would none be better replaced with not any, or not one? If not any, use a plural verb; if not one, use a singular. Here, there is reason to emphasize that "not even one" of the inmates was treated fairly, so the verb should be singular.

Not a single one of the inmates was given a fair trial.

Don't worry too much about sentences like this last example – since the intention behind the use of none in such cases can generally only be determined by context, and is often subtle, the GMAT is very unlikely to include them in the Sentence Correction section.

None is singular when: The noun following none is singular OR None means "no part of" None means "not one" or "not a single one"

None is plural when: The noun following none is plural OR None means "not any"

C. Collective Nouns

E. Neither / Either