What are nouns?
Nouns, not including pronouns and proper nouns, come in three basic categories: concrete, abstract, and gerunds (-ing nouns).
Concrete nouns are those that can be perceived by the senses (touch, taste, sight, sound, smell), by legal recognition, or mutual agreement. In other words, these are “real” things. Examples of concrete nouns are dog, police office, cabbage, music, odour, and so on in terms of the five senses. In legal terms, a company, a contract, a job are things that can’t necessarily be sensed, but are nonetheless real things. The basic idea here is that concrete nouns are people, places, and things.
Abstract nouns are those that cannot be sensed and include ideas, concepts, beliefs, or states of being. These include love, honour, democracy, freedom, loyalty, approval, and so on. These are real in the sense that we can feel them or think about them, but we cannot grasp them or put them on paper.
Gerunds, for the most part, are activities. Shopping, eating, smoking, and walking are examples of gerunds. They mostly refer to external activities or internal thought processes or feelings (thinking, feeling, etc.). Activities are thus concrete, while internal processes are abstract.
Types of nouns
Nouns can be classified as countable or uncountable (noncountable). Whether they are concrete or abstract does not affect whether they are countable or not. Music, a concrete noun, cannot be counted, so you cannot pluralize music into musics. Likewise, some abstract nouns can be counted and pluralized, such as freedom. A person might have many freedoms, such as freedom of speech, the freedom to vote, and so on.
Countable nouns, as the name suggests, can be counted. Examples of these are chair(s), sister(s), mouse (mice), culture(s), etc. They can be counted because they are individual, self-contained elements; you can have one chair, two chairs, etc. Furniture, on the other hand, includes chairs, tables, and sofas and is a general term that includes many different elements and cannot be a self-contained unit.
Uncountable nouns cannot be counted because they do not come in divisible units, meaning they cannot be divided, added to or subtracted from, doubled, tripled, etc. Love, for instance, cannot be cut into half or doubled to two loves. However, some uncountable nouns can represent countable things. Love, the feeling, is uncountable. Loves, however, can refer to people or activities a person loves (John has many loves, like travelling and reading, but his greatest love is music.—you can substitute passions for loves in this example; passion is also an uncountable noun.)
Likewise, some countable nouns come in such great quantities that it is normally easier to treat them as uncountable. For example, you can count each individual hair on your head, but that would be a very difficult task for most people. It is better, then, to say that you have black hair rather than black hairs. As you get older, though, it is alright to say you have a few grey hairs.
So how can you count uncountable nouns? In some cases you can count the individual unit of the concrete noun. Sand is an uncountable noun. Yet we can count grains of sand. We can count strands of hair, or loaves/slices of bread. We can also count things by a unit of measure, such as a liter of water or a psi (pound per square inch) of air. We can’t count money, but we can count dollars, yen, and rubles. We can count containers, such as a carton of milk, a news article, or a gulp of air. Certain nouns come with their own specific counters, such as a head of lettuce, a bunch of grapes, or a herd of cattle. In other words, uncountable nouns have other, countable nouns with which we can count them.
Keep in mind that most gerunds are uncountable, especially those that signify an activity. However, some –ing nouns are actually not gerunds but are simple nouns. Feeling, as in I have a bad feeling about this is a regular noun and is countable and can be pluralized (feelings). A person goes through many feelings in an average day. A hearing can be a legal event in which a judge hears arguments from the prosecution and defense. The key to knowing whether an –ing noun is a gerund or a simple noun is to understand if there is an action involved or if it is a thing. Smoking is a gerund because it involves the action of inhaling the smoke from a cigarette. A meeting is a simple noun that involves a set gathering of people for a discussion on a topic. You cannot use smokings, but you can have meetings.
Remember that a gerund is essentially a verb that functions as a noun.
Lastly, we need to look at collective nouns. These are nouns that represent a group of things, animals or people. Examples of collective nouns are fleet (of cars), staff (members), herd (of cows), and so on. The main thing to keep in mind here is that collective nouns are often singular and agree with a singular verb and pronoun. For example, This company’s staff is the best in the business. Even though staff consists of many employees, the grouping is singular. However, there are occasions when collective nouns can be used as plurals if we are referring to the individuals within the group (The staff are invited to submit any complaints they have to the manager—in this case, each individual is invited to do this, not the group as a whole). If you are not sure if the collective noun subject and the verb agree, either change the subject, or add the individual members/pieces of the group (The fleet is due for an upgrade.—The cars in the fleet are due to be replaced by newer models.)
It is also important to remember that collective nouns can be plural (fleets, staffs, herds, etc.).
What is the function of a noun?
A noun is used as the subject of a clause, the object of a clause, the object of a preposition, or as an adjective to another noun.
When used as an adjective, we refer to the noun as a compound noun (2 nouns) or noun group (3 or more nouns). An example is a high school student, where both school and student are nouns, but school works like an adjective to describe the student. Compound nouns and noun groups have a head noun, the last noun in the series, and will function in one of the capacities listed above. Thus, in university course professor, professor is the noun that may be the subject or object of a clause, or object of a preposition; the nouns university and course act as adjectives to describe the type of professor we are talking about.
In much the same way, a possessive noun, a noun that ends with apostrophe s (‘s) or (s’), acts as an adjective. Thus, the professor’s lecture is a compound noun where the lecture is the head noun and shows that it belongs to the professor.
Of course, there are also noun phrases and noun clauses. These will be looked at in the advanced grammar section.
The easiest way to recognize a noun is its use in the context of the sentence. For instance, if it is not performing an action, then it is not a verb. If it is not modifying a verb or adjective, then it is not an adverb. Of course, nouns can be used as adjectives to modify other nouns, so you need to look out for these compounds.
However, there are also more direct ways to recognize a noun even if the word or context is unfamiliar. Certain suffixes (word endings) can tell us the word’s part of speech.
-ness, -sion, -tion, -ation, -ance, -ence, -ure, -ment, -age, -ery, -ity, -ism, -ist, -th, -y, -ty, -ant, -ent,
-ar, -er, -or, -arian, -ee, -eer, -dom, -ship, -hood, and –al are noun suffixes (be aware, though, that –al can also be an adjective suffix)
awareness, decision, invitation, fixation, disturbance, failure, management, package, machinery, mobility, Communism, typist, width, honesty, safety, assistant, dependent, liar, interpreter, advisor, vegetarian, employee, engineer, freedom, friendship, brotherhood, arrival.
That being said, the best way to understand if a word in a sentence is a noun is to understand its function. For example, smile can be either a noun or a verb. In the sentence, Her smile put everyone at ease, smile is obviously a noun because it acts as an object to the possessive adjective her, and it also is responsible for the main verb put. On the other hand, in She smiled at everyone to put them at ease it is obviously a verb as it functions as the main, tensed action of the sentence, and is the action that the subject she does.