Correcting Subject-Verb Agreement — I can correct common subject–verb agreement errors in longer sentences.

Why Does Subject-Verb Agreement Exist?

Every language needs rules to keep meaning clear. In English, one of the oldest and most important rules is subject-verb agreement — the idea that a verb must match its subject in number. If the subject is singular (one thing), the verb takes a singular form. If the subject is plural (more than one), the verb takes a plural form. This rule has been part of the English language for over a thousand years, and it helps listeners and readers instantly understand who or what is doing the action.

English didn't always look the way it does today. Over the centuries, the language simplified dramatically. Old English had dozens of verb endings depending on person, number, and tense. Modern English has trimmed most of those away, but the third-person singular "-s" ending survived — and that's exactly where agreement errors sneak in. Let's look at how we got here.

So here's the challenge: English only has one visible agreement marker left — that little "-s" on present-tense, third-person singular verbs. In short sentences like "She runs," spotting agreement is easy. But in longer sentences, the subject and verb can be separated by many words, making it surprisingly hard to match them correctly. That's the problem this lesson solves.

Core Principles of Subject-Verb Agreement

Before you can fix agreement errors, you need to understand the foundational rules. These five principles cover the vast majority of situations you'll encounter in longer sentences. Master them, and you'll catch errors that trip up even experienced writers.

Seeing Agreement in Action

One of the best ways to understand subject-verb agreement is to see the sentence structure laid out visually. The diagram below shows how intervening phrases can separate a subject from its verb, creating the conditions for an error. Notice how the subject "team" connects directly to the verb "has," even though several words sit between them.

The key strategy you see in this diagram is called "crossing out the clutter." When you mentally remove the prepositional phrase, the sentence simplifies to "The team has won." That's clearly correct. Whenever a sentence feels tricky, strip it down to its core subject and verb, check whether both are singular or both are plural, and you'll have your answer.

The Mechanics: How Agreement Works in Detail

Subject-verb agreement isn't a math formula, but it does follow a clear, logical pattern. Think of it as a decision tree: you identify the subject, determine its number, and then select the correct verb form. Let's break down the mechanics for the trickiest sentence patterns you'll encounter.

Pattern 1: Prepositional Phrase Interruptions

A prepositional phrase begins with a preposition (of, in, with, at, for, between, among, etc.) and ends with a noun. These phrases often sit between the subject and verb, and the noun inside them can have a different number than the subject. The rule is simple: the object of a preposition is never the subject. For example, in "The color of the curtains matches the rug," "color" is the singular subject, and "curtains" is just the object of "of."

Pattern 2: Compound Subjects

When two or more subjects are joined by "and," they form a compound subject that is plural: "Peanut butter and jelly are in the pantry." However, when subjects are joined by "or," "nor," "either...or," or "neither...nor," the verb agrees with the subject closest to it. So you'd write "Neither the coach nor the players were ready" (verb matches "players"), but "Neither the players nor the coach was ready" (verb matches "coach").

Pattern 3: Indefinite Pronoun Subjects

Pattern 4: Inverted Sentence Order

Sentences that begin with "there" or "here" flip the usual subject-verb order. "There" and "here" are never the subject — they're just sentence starters. You must look after the verb to find the real subject. In "There are several problems with that plan," the subject is "problems" (plural), so the verb must be "are." A common mistake is writing "There is several problems" because "there" feels singular.

Common Error Types — A Classification

Now that you know the rules, let's look at the specific error patterns that appear most often in student writing and on standardized tests. The diagram below organizes these errors into a flowchart so you can quickly diagnose what went wrong in any sentence.

Quick-Reference Error Examples

Worked Example: Correcting Errors Step by Step

Let's walk through a complex sentence and apply the strategies you've learned. This example is deliberately tricky — it combines multiple error traps in a single sentence, just like you might see on a test or in a writing assignment.

Proofreading Strategies — Strengths & Limitations

Different strategies work better in different situations. Some approaches are quick and great for tests, while others are more thorough and suited for essay revision. Here's how the most popular techniques compare.

Connection to Advanced Grammar Concepts

Subject-verb agreement is your foundation, but the grammar world goes much deeper. As you advance in your writing, you'll encounter related concepts that build on the same logic. Here's a preview of where these skills lead.

The skills you're building now — finding the subject, checking its number, and selecting the matching verb — are the same skills that power every grammar correction you'll make in the future. Whether you're writing a college application essay, editing a research paper, or just sending a professional email, subject-verb agreement is the backbone of clear, credible writing.

Practice Problems

Now it's your turn. For each sentence below, decide whether the underlined verb is correct or incorrect. If it's incorrect, identify the error and provide the corrected verb. Try to use the strategies from this lesson — cross out the clutter, find the true subject, and check the number.

Lesson Summary