Subject: What is a Subject?

By Carly Forsaith, updated on March 7, 2023

What is a subject? One of the most basic grammar concepts, subjects are everywhere. In fact, you won’t find a complete sentence without one. In this article, we’ll dive deep into the intricacies of a subject, how to identify it, and how to use it.

In short, the subject of a sentence is the thing that performs the action or has the action of the verb done to it.

This guide is part of our free online Grammar Book.

What Is a Subject in a Sentence?

Despite my short explanation of a subject in the introduction, it’s difficult to boil down the definition of a subject to something clear-cut. There are many variations of what a subject might look like and the role it performs in a sentence.

Let's start with the basics. Any sentence contains a subject and a predicate. The predicate complements the subject by giving information on what is happening to it or what it is doing. See the example below with the subject in bold and the predicate underlined:

The couple chose the venue.

Subjects can do one of several things:

  • Perform the action described by the verb
    The music blasted through the streets.
  • have the action of the verb performed on them
    Helen received an honorary award for her work with the university.
  • be described
    He was a tall man.
  • be identified
    That is the bed I wanted.

As you can see from the above examples, what the subject does is defined by the predicate, specifically the verb. The rest of the predicate serves to give additional information.

Which Parts of Speech Can Be Subjects?

The subject is usually a noun but can also occasionally be other things. Take a look at the following sentences that use different types of subjects (in bold).

The plants need watering. (noun)

They arrived early at the party. (pronoun)

Running calms me down. (gerund)

The rabbit with brown fur is the cutest. (noun phrase)

Sleeping under the stars is the best feeling. (verb phrase)

In a rocking chair is the best place to read a book. (prepositional phrase)

To parent a child requires a lot of patience. (infinitive)

A noun is typically found at the beginning of a sentence unless an introductory phrase precedes it. Look at the following example where the subject 'we' doesn't come in until halfway through the sentence:

In order to win, we must train more often.

Finding the Subject

What if you want to find the subject of a sentence, but you're not sure what you're looking for, even with everything we've learned so far? I'm going to show you one simple trick.

Remember, a subject always acts upon or is acted upon by a verb. So if you want to find the subject in a sentence, ask yourself, who or what is being "verbed?"

Take the following sentence as an example. The verb is 'sleeping,' so ask yourself, what or who is sleeping? It's the dog, of course. Therefore, the subject of this sentence is 'dog.'

The dog was sleeping soundly on the couch.

Different Types of Subjects

Now you've had an introduction to what a subject is, and I want to tell you about the three different types of subjects that exist.

Simple Subject

A simple subject is made up of one word. So if you ignore all the additional words around it, such as determiners and modifiers, what is left? A single word.

The brown car over there is mine.

In the above sentence, 'car' is the subject.

Complete Subject

A complete subject is the main word (simple subject) plus the determiners and modifiers that relate to it. Using the previous example:

The brown car over there is mine.

While 'car' is the simple subject, the phrase 'the brown car' is considered to be the complete subject.

Let's look at a different example:

My car, a Renault Scenic, is parked over there. 

The make of the car is a part of the complete subject. Here's another one for the road:

Your first guitar lesson will take place next Monday.

Compound Subject

When two or more simple subjects come together, they form was is called a compound subject. In the following sentence, the noun 'husband' and pronoun 'I' are both the subject. The determiner 'my' and conjunction 'and' are included, and all three words form the compound subject.

My husband and I are hosting a dinner at the weekend.

Don't forget to use the correct verb form: with compound subjects, you'll want to conjugate the verb in its plural form. This is demonstrated in the above example, where the verb used is 'are.'

More About Subjects

We've pretty much covered the basics of what a subject is and how to recognize one. But there are a few more things you might like to know about them. Read on if you'd like to learn more.

Dummy Subjects and Implied Subjects

When we were looking at the different parts of speech that can be subjects, I left out two kinds of subjects: dummy and implied. I didn't mention them because they don't fall into specific parts of speech, as that will depend on the context. Let's learn more about those now.

A dummy subject is a word that takes on the role of a subject when there is none attached to the verb. There are two possible dummy subjects: it and there.

Let's look at some examples.

It is too late to start cooking now.

There are sheep in the field.

As for implied subjects, they happen when there isn't a stated subject in the sentence, but you can understand what the subject is from the context. Implied subjects are common with the imperative mood:

Call me tomorrow.

The implied subject here is 'you.'

They are also common in colloquial contexts:

See you later.

The implied subject here is 'I.'

Subject-Verb Agreement

The thing about subjects is that the whole sentence revolves around them, and in particular, the verb. The verb conjugation will depend on the subject. Choosing the correct verb form to match the subject is called subject-verb agreement. Look at the following examples and see how the change in subject affects the verb form.

The tiger chases the gazelle.

I chase the gazelle.

If you were to say, "The tiger chase the gazelle," that would be incorrect subject-verb agreement.

Concluding Thoughts

That concludes this article on the parts of sentences known as subjects.

Let's summarize what we've learned:

  • Subjects perform the action of the verb or have the action performed on them
  • Many parts of speech can take on the role of subject
  • There are three types of subject: simple, complete, or compound

If you'd like to learn about more grammar concepts, visit our ever-growing Grammar Book database on our blog.

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Written By:
Carly Forsaith
Carly Forsaith is one of the lead freelance writers for Carly is a copywriter who has been writing about the English language for over 3 years. Before that, she was a teacher in Thailand, helping people learn English as a second language. She is a total grammar nerd and spends her time spotting language errors on signs and on the internet.

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