As a general rule, nouns are classified as count nouns or noncount nouns.
A
count noun is one that forms a plural, and as such can be used with a numeral, can be modified by words such as “many” or “few,” or can be used with the indefinite article “a” or “an.” Generally, a count noun refers to things that can be divided into smaller units that are separate and distinct from one another. Examples of count nouns:”apple” (singular: “an apple”; plural: “three apples,” “many apples,” “few apples”); “bottle” (singular: “a bottle”; plural: “five bottles,” “many bottles,” “few bottles,”); “cars” (singular: “a car”; plural: “cars,” “seven cars,” “many cars,” “few cars”).
A
noncount noun is something that can’t be counted because it is considered as a whole that can’t be divided into parts. It often refers to an abstraction or a collectivity. As such, a noncount noun—in contrast to a count noun—isn’t used with a numeral and can neither be modified by the words “many” or “few” nor used with the indefinite article “a” or “an.” Examples of noncount nouns: “heat” (we can’t say “three heats,” “many heats,” “few heats,” or “a heat”); “cowardice” (we can’t say “three cowardices,” “many cowardices,” “few cowardices,” or “a cowardice”); “anger” (we can’t say “six angers,” “many angers,” “few angers,” or “an anger”). In fact, as a rule, we can’t add the suffix “s” or “-es” to a noncount noun at all to make it plural.
So, you ask, how do we decide whether to use the singular or plural form of the verb for a particular noun?
As a general rule, we use the singular form of the verb when a count noun is in its singular form—meaning that only one of it is being referred to: “An apple
drops from the table.” “The car
runs on electricity.” Of course, we use the plural form of the verb when a count noun is in its plural form: “The apples
drop from the table.” “The cars
run on electricity.”
In contrast, with noncount nouns, we always use the singular form of the verb: “The heat
makes everyone perspire profusely.” “Cowardice
is a punishable act in war.” “Anger
gets the manager in trouble very often.” It would be grammatically unforgivable to say “The heats
make everyone perspire profusely,” “Cowardices
are a punishable act in war,” and “Angers
get the manager in trouble very often.” However, we can evoke a plural sense for a noncount noun by modifying it with a count noun, as in the following reconstructions of the same three sentences above: “
The repeated blasts of heat make everyone perspire profusely.” “
Acts of cowardice are a punishable act in war.” “
His recurrent fits of anger get the manager in trouble very often.”
Taking the above discussions into account, here’s how to use the verb for the three count nouns you specified in your posting:
“The sea
is rough at this time of day.”
“The seas in the Western Pacific
are often rough during the typhoon months.”
“Tonight, the rain
is expected to be strong.”
“The whole week next week, the rains
are expected to be strong.”
“The rain
falls in torrents.”
“In both towns, the rains
fall in torrents.”
For a more comprehensive discussion of count and noncount nouns, click
this link to Literacy Education Online (LEO).
