What can function as a subject?
For many non-native users of English, one of the difficulties in both writing and reading is knowing what the subject of the sentence is; in complex and compound sentences this becomes even more challenging when you take into consideration that sentences of these types contain more than one subject in the various clauses.
The difficulty lies in the fact that a subject can take many forms. The most commonly used subject is a simple noun or pronoun:
Boys like to play with their toys. subject: boys
Jennifer visited her grandmother at the hospital. subject: Jennifer
They called the fire department to investigate the cause of the fire. subject: They
Subjects may appear in other forms as well:
The noun phrase
Noun phrases are groupings of a noun and all its modifying words. These words can be an adjective, an article, a possessive pronoun, a preposition or a prepositional phrase, etc. Although the noun in the phrase (called the head noun) is the actual subject, the entire phrase must be collectively viewed as the subject because the noun alone would be incomplete:
The girl with the ponytail asked the boy sitting behind her to stop pulling it.
The head of the sales department, John Woo, was promoted to senior manager of his section. (in this sentence, John Woo is also the subject, but is being used in this sentence as an appositive, meaning that the name identifies the title: the head of the sales department = John Woo)
The top five students will be considered for scholarships.
NB: Do not confuse the noun in the prepositional phrase for the subject. The subject is always the head noun only.
Nouns that are joined by the conjunction and are called compound subjects. The whole subject is considered a plural subject and must agree with a plural verb.
Linda and Scott often shop together.
Fishing nets are indiscriminate; both tuna and dolphins often get caught in them, though tuna is usually the targeted catch.
Beth, Joan, and Tina have been selected to represent the company at the conference next month.
A gerund is simply the –ing form of a verb that is being used as a noun. Gerunds are usually used in regards to an activity, and this is usually done when no natural noun exists to talk about the activity. For example, swimming, smoking, and writing are gerunds for their respective activities for which no simple noun exists. Thinking, on the other hand, is also an activity; however, there are nouns that can replace it—contemplation, for instance. If, you are thinking about something in particular, though, you would most likely use the gerund as the subject of the sentence that talks about this.
On the other hand, sometimes we want to discuss the activity, not the process. Aimless thought and thinking aimlessly are two different things. The first focuses on the thoughts themselves, while the latter focus on the person doing the thinking. In other words, we need to look at the focus of the subject of the sentence when we decide to use a natural noun or a gerund.
As a subject, gerunds are to be treated as simple nouns:
Smoking is bad for your health.
Swimming regularly does wonders for your posture.
Thinking too much about the unfairness of life will only make you more and more cynical.
Thinking is something that all of us do every day. Or: Contemplation is an activity that we all engage in every day.
Gerund phrases, like noun phrases, include the gerund itself, as well as all its modifiers:
Feeling good about yourself is more important than looking good to others.
A subject may also appear in the form of a noun clause, which is a dependent clause that cannot, on its own, be a complete sentence. It is important to remember that a noun clause will also have a clause marker (conjunction) and its own subject:
Whether I go to the meeting or not depends on my schedule that day.
What most people watch on television seems like a waste of time to me.
That she said something in the first place is the problem; she should have stayed out of it.
Whoever delivers the product is also responsible for its condition.
Some subjects can actually be verbs in the infinitive form. The infinitive form of a verb suggests the idea of that action, not the action itself:
To live a full and happy life is the duty of every person.
Beginning a sentence with an infinitive phrase, however, is rare. More often people introduce the subject later in the sentence and begin with what is a called a “dummy” subject, such as it or there
In some sentence we use it as the subject. However, it usually stands in place for the subject that actually appears later in the sentence. This is especially true of sentences that have a noun clause or infinitive phrase as their subjects.
We can also use there (is/are/was/were) to begin a sentence when the actual subject appears later. The reason for beginning a sentence with a dummy subject is that beginning the sentence with the actual subject might seem awkward or even snobby (too high-minded and not simple enough):
To look at yourself in the mirror before you leave the house in the morning is always a good idea.
It is always a good idea to look at yourself in the mirror before you leave the house in the morning.
Various drinks were served at the party.
There were various drinks served at the party.
One final note: Keep in mind that in certain situations, a subject can appear after the verb in cases of inversion:
Not only is he friendly, he is also very helpful.
Down the hill rolled the car.
Had the police chief’s assistant known about the evidence, he wouldn’t have wasted all that time interviewing the witnesses.