Subject-verb agreement means the verb must match its subject in number. A singular subject takes a singular verb (she works), and a plural subject takes a plural verb (they work). The main difficulty is finding the real subject when other words come between it and the verb.
The basic rule
In the present simple, the verb changes only for the third person singular. Add -s or -es when the subject is he, she, it, or a singular noun: The student works, the city grows, the teacher teaches. With I, you, we, they and plural nouns, use the base form: The students work.
The verb be changes more: I am, he is, they are in the present; I was, they were in the past. Have and has follow the same pattern: she has, they have.
A such as can or must never takes -s: She can drive, not She cans drive. The same is true for the verb after do: Does she work? not Does she works?
- He works in a bank. · They work in a bank.
- The city has a new park. · The cities have new parks.
Find the real subject
Most mistakes happen because words come between the subject and the verb. The verb agrees with the subject, not with the nearest noun. In The quality of the roads has improved, the subject is quality, so we use has. In The students in my class are friendly, the subject is students, so we use are.
A good method is to cross out any phrase that begins with of, in, with or who, and then find the noun that remains. The quality ... has improved. The students ... are friendly.
Special cases that cause errors
Some subjects look plural but take a singular verb. Everyone, everybody, everything, each, every, someone, nobody and no one are all singular: Everyone in the class speaks English. Each of the students has a laptop. nouns also take a singular verb: The information is useful. News and economics are singular too.
Two common phrases need care. The number of takes a singular verb (The number of students has risen), but a number of means several and takes a plural verb (A number of students have complained). One of the takes a singular verb because the subject is one: One of my friends works in a hospital.
When two subjects are joined by and, the verb is plural: The teacher and the student are talking. When they are joined by either ... or or neither ... nor, the verb agrees with the nearest subject: Neither the teacher nor the students know the answer.
- Singular: everyone, each, every, nobody, someone, news, information
- Plural: people, police, the poor, both, several, many
- Singular: the number of, one of the, the amount of
- Plural: a number of, a lot of students, two of the
There is and there are
In sentences that begin with there, the verb agrees with the noun that comes after it: There is a problem. There are several problems. In speech, people often say There's for both, but in writing, keep the agreement. With a list, speakers often match the verb to the first item, as in There is a bus and a train. In formal writing, the safest choice is to rephrase so that the subject comes first: A bus and a train are available.
Mistakes to avoid
The classic mistakes are leaving out the third person -s (She work in a bank), adding -s to a plural subject (The students works hard), and matching the verb to the nearest noun (The cost of these courses are high). Another is using a plural verb with an noun (The news are bad).
A reliable check is to read your sentence and say the subject and the verb alone: cost is, students work. If those two words agree, the rest of the sentence is usually safe. Do this check for each long sentence in your IELTS essay, since long sentences are where agreement errors hide.
In IELTS Speaking
Agreement errors are common in speech because you do not have time to check. The best way to improve is to slow down slightly at the start of a sentence, and to hear the subject in your mind before you say the verb. Listen to your own recordings and mark every present simple verb with a third person subject. The pattern of errors will show you what to practise.
Who finds this hard?
- Chinese speakers: Chinese verbs do not change for person or number, so the third person -s is a new habit that needs constant checking.
- Japanese speakers: Japanese verbs do not change for the subject, so learners often miss the -s or add it to the wrong subject.
- Korean speakers: Korean verbs do not agree with the subject in number, so the English pattern has to be learned from scratch.
- Turkish speakers: Turkish has agreement endings but a different system, and a plural noun for things can take a singular verb, which leads to mistakes in English.
IELTS tip
In Writing Task 2, check the verb in every long sentence by finding the real subject and ignoring the phrase between the subject and the verb. In Speaking, pay special attention to he, she, it and singular nouns in the present simple, and to there is and there are.
Frequently asked questions
What is subject-verb agreement?
It means the verb form must match whether the subject is singular or plural. In the present simple, a third person singular subject takes -s.
Is the number of singular or plural?
The number of takes a singular verb. A number of means several and takes a plural verb.
Do collective nouns like government take a singular or plural verb?
In British English, both can be used, depending on whether you think of the group as one unit or as many people. Keep your choice consistent within a paragraph.
How can I find the subject of a long sentence?
Cross out phrases beginning with of, in or who, then find the noun left before the verb.
Sources
- Swan, M. (2016). Practical English Usage (4th ed.). Oxford University Press.
- Biber, D., Johansson, S., Leech, G., Conrad, S. and Finegan, E. (1999). Longman Grammar of Spoken and Written English. Longman.