Subject-Verb Agreement Errors and How to Fix Them
Agreement errors slip past writers because they feel right when read quickly. Here are the patterns that cause them.
Agreement Errors Hide in Long Sentences
Subject-verb agreement is simple in theory: a singular subject takes a singular verb, a plural subject takes a plural verb. The cat runs, the cats run. Anyone can recite the rule. The errors do not come from not knowing it. They come from sentences where the subject and the verb are so far apart, or so tangled with other nouns, that your ear loses track of which word is actually the subject.
These errors feel right when read quickly because the nearest noun agrees with the verb, even if that noun is not the subject. The checker misses them for the same reason. Fixing them means knowing the specific patterns that set the trap.
The Patterns That Cause Most Agreement Errors
| Pattern | Example of the Error | The Fix |
|---|---|---|
| Words between subject and verb | "The list of tasks were long" (list is singular) | Find the real subject: "The list of tasks was long" |
| Subjects joined by and | "Research and writing is required" (two things, plural) | Use a plural verb: "Research and writing are required" |
| Each, every, one as subject | "Each of the reports are due" (each is singular) | Use singular: "Each of the reports is due" |
| Collective nouns | "The team are winning" (US usage treats team as singular) | Use singular in US English: "The team is winning" |
| Either/or and neither/nor | "Neither the manager nor the staff was told" | Verb matches the nearest subject: "were told" |
The Nearest-Noun Trap
The single biggest source of agreement errors is the phrase wedged between the subject and the verb. You write "The box of chocolates were a gift," and it feels fine because chocolates sits right next to were and chocolates is plural. But the subject is box, which is singular, so the verb should be was.
The fix is mechanical. When you have a subject followed by a phrase starting with of, ignore everything in that phrase when choosing the verb. The box of chocolates was a gift. The pile of leaves was ankle-deep. Train yourself to skip past the of-phrase and you eliminate most of these errors.
When you are unsure, mentally cross out any phrase set off by commas or starting with of, along with the words there and here at the start of a sentence. What remains is the bare subject and verb, and the agreement becomes obvious. This takes two seconds once you build the habit.
How to Catch Agreement Errors in Your Own Writing
- 1Underline the subject and the verb in long sentences
For any sentence over fifteen words, mark which noun is the subject and which word is the verb. If they are more than a few words apart, this is where agreement errors hide, and a quick check prevents most of them.
- 2Watch the of-phrases
Whenever you see a subject followed by of something, double-check the verb against the first noun, not the noun inside the phrase. This one pattern accounts for a large share of all agreement mistakes in formal writing.
- 3Check indefinite pronouns
Words like each, every, everyone, anyone, somebody, and none trip writers up. Treat each, every, everyone, and anyone as singular. For none, match the noun it refers to: none of the pie was eaten versus none of the cookies were eaten.
- 4Resolve either/or and neither/nor by proximity
When two subjects are joined by or or nor, the verb agrees with the nearer one. "Neither the director nor the actors were ready," because actors is closer to the verb and is plural. Read it back with just the nearest subject to test it.
- 5Read the sentence with just the subject and verb
Strip out every modifier and interrupter, then read what is left. "The data is reliable" or "the data are reliable," depending on your field, with nothing else in the way. If the stripped version sounds wrong, you have your answer.
The Tricky Cases Worth Memorizing
A few words cause disproportionate trouble. Data is treated as plural in scientific writing and singular in everyday usage; pick one and stay consistent within a document. None can be singular or plural depending on what it refers to. And collective nouns like team, staff, and committee are singular in American English but often plural in British English, so the right answer depends on your audience.
Titles of works, such as movies and books, are singular even when the title contains a plural word. "The Two Towers is my favorite" is correct, because the title is one thing. Get these few cases right and you will have covered the exceptions that catch most writers.
Agreement errors do not mean you do not know grammar. They mean a long sentence hid the subject from you for a moment.
Why Checkers Miss What You Can Catch
Grammar checkers flag simple agreement errors but miss the ones buried in long, complex sentences, exactly where they matter most. They also struggle with collective nouns and field-specific conventions like treating data as plural. The checker is a first pass, not a final one.
The reliable method is your own two-step read: find the subject, find the verb, and confirm they match with the interrupters stripped away. Once that becomes automatic, agreement errors nearly disappear from your drafts. If you want a second pass on a sentence that still feels off, AI Humanizer Lab's grammar checker can flag the mismatch and suggest the corrected verb form.
Make your writing sound human
Humanize AI-generated text in one click with AI Humanizer Lab.
Try for free