Countable nouns have a plural: one idea, two ideas. Uncountable nouns such as information and advice do not, so they never take -s. To get them right, check the noun after every counting word and learn the academic nouns that stay singular. Seven rules and 40 exercises with answers train both habits on real campus sentences.
40 questions8 levels of 57 rulesLevel 1 free
1 in 2
What we measured
of the 8,000 most recent writing responses we evaluated had at least one singular or plural form corrected.
How do countable and uncountable nouns work?
After many, several, these or two, the noun needs -s
Some words announce that more than one thing is coming: many, several, both, these, those, a few, and every number above one. The noun after them must be plural, even when an adjective sits in between. That middle word is where students slip: in "these unhealthy food", the eye stops at unhealthy and the -s never arrives. Look past the adjective to the noun.
Right:Several students missed the bus this morning.
Right:Both of my sisters work on campus.
Right:These unhealthy foods are cheap and easy to find.
Not:She has many friend in her dorm.Instead:She has many friends in her dorm.
Not:These unhealthy food are popular on campus.Instead:These unhealthy foods are popular on campus.
Not:I waited for two hour.Instead:I waited for two hours.
Uncountable nouns never take -s
Some nouns name a mass or an idea, not separate items, so English does not count them. They have no plural, however large the amount. Learn these ten as a group: information, research, advice, equipment, knowledge, homework, feedback, evidence, furniture, luggage. Use some, a lot of or much in front of them. To count them, add a unit word: a piece of advice, two pieces of furniture.
Right:I found some useful information online.
Right:My tutor gave me a lot of feedback.
Right:She gave me a great piece of advice.
Not:We need more researches on this topic.Instead:We need more research on this topic.
Not:I have two homeworks tonight.Instead:I have two homework assignments tonight.
Not:He bought a new furniture.Instead:He bought a new piece of furniture.
Much and little for uncountable nouns, many and few for plurals
Use many and few with plural nouns: many students, few examples. Use much and little with uncountable nouns: much time, little evidence. On their own, few and little mean "not enough". With a in front, they mean "some": a few friends, a little help. A lot of works with both groups, and it usually sounds more natural than much in a positive sentence: a lot of homework.
Right:How many pages do we have to read?
Right:There is not much time left.
Right:I have a few questions about the essay.
Not:I do not have many money.Instead:I do not have much money.
Not:There is few evidence for this idea.Instead:There is little evidence for this idea.
A number of for plurals, an amount of for uncountable nouns
These two phrases work like many and much. A number of goes with plural nouns, because you can count what follows: a number of students, a large number of problems. An amount of goes with uncountable nouns, because you measure what follows: a small amount of money, a large amount of research. Do not write "an amount of students". If you are unsure, a lot of works with both.
Right:A number of students asked for more time.
Right:The lab uses a large amount of water.
Not:A large amount of people attended the talk.Instead:A large number of people attended the talk.
Not:A number of research supports this idea.Instead:A large amount of research supports this idea.
One of the needs a plural noun, every needs a singular one
After one of the, one of my and each of the, the noun is plural, because you are picking one item from a group: one of the reasons, each of the rooms. The opposite is true straight after each or every: the noun stays singular, as in every student and each class. So "one of the reason" and "every students" are both wrong.
Right:One of the reasons is cost.
Right:One of my friends lives in Seattle.
Right:Every class has a final project.
Not:One of the problem is the noise.Instead:One of the problems is the noise.
Not:Every students needs a laptop.Instead:Every student needs a laptop.
Learn the irregular plurals you will actually use
A few common nouns do not add -s. Child becomes children and person becomes people, so childrens is never right and peoples is wrong in ordinary sentences. Two academic words keep their Greek endings: one criterion, two criteria, and one phenomenon, two phenomena. That means "a criteria" is wrong, because criteria is already plural. These plurals take plural verbs: the criteria are clear.
Right:Three children were playing near the fountain.
Right:Many people take the train to campus.
Right:The criteria for this award are strict.
Right:A solar eclipse is a rare phenomenon.
Not:My professor has two childrens.Instead:My professor has two children.
Not:One important criteria is cost.Instead:One important criterion is cost.
Adjectives never take -s
English adjectives do not change for plural nouns. Write different ideas and important reasons, never differents or importants. The same goes for a noun or a number phrase doing the job of an adjective before another noun: a ten-page paper, a two-hour exam, a computer lab. The -s normally goes only on the last noun, so it is three computer labs, not three computers labs.
Right:We discussed several important topics.
Right:I wrote a ten-page paper.
Right:There are three computer labs on this floor.
Not:My friends have differents opinions.Instead:My friends have different opinions.
Not:This is a two-hours exam.Instead:This is a two-hour exam.
Where this costs you marks on the TOEFL
Nouns are not tested on their own, because the TOEFL iBT has no separate grammar section. They count inside Writing and Speaking, and the Academic Discussion is a likely place for them to show. You are giving an opinion on a topic, so you often write about groups in general, with phrases such as many students and several reasons, and each one needs a plural. Academic nouns are a second risk. Forms such as researches and informations stand out because they are the very words you chose to sound advanced. In the Interview and Listen and Repeat, the danger is a final -s that you know but do not pronounce. Before you submit, check each counting word and the noun that follows it.
If your first language is...
First language
What to watch for
Chinese, Japanese, Korean, Vietnamese and Thai speakers
Your language usually shows number through context or a counting word, not a plural ending, so "three book" sounds complete. English needs the number and the -s together. The counter words you already use do help in one place: "a piece of advice" works much like a counter, so that pattern may come easily.
Spanish, Portuguese and French speakers
Adjectives in your language change with the noun, so "differents ideas" is a direct translation. In English, only the noun changes. Watch the nouns that are countable for you but not in English: consejos, conselhos and conseils are plural, and so are informaciones, informações and informations. In English, advice and information have no plural.
Turkish and Persian speakers
A noun after a number stays singular in both languages: Turkish iki kitap and Persian do ketab both mean, word for word, "two book". That habit carries straight into English as "three student". In English, the number does not replace the -s. You need both.
Hindi and Urdu speakers
Many Hindi and Urdu nouns look the same in the singular and the plural, as in ek saal, do saal (one year, two years), so "two year" can slip through. Forms such as informations, equipments and furnitures are also common in English across South Asia, so they may sound right to you. On the exam, use the standard forms with no -s.
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What is the difference between countable and uncountable nouns?
Countable nouns name things you can count one by one, so they have a plural: one book, two books. Uncountable nouns name a mass or an idea, so they have no plural and usually take no a or an: information, advice, research. A learner's dictionary marks each noun as countable or uncountable, so look up any word you are unsure of.
Can I say "informations" or "advices"?
No. In standard English, information and advice are uncountable, so they never take -s, and the same goes for research, equipment, homework, furniture, luggage and feedback. To talk about one item, use a unit word: a piece of information, two pieces of advice. In speech and writing alike, the unit word takes the -s, and the noun stays the same.
Can a noun be both countable and uncountable?
Yes, and the meaning changes. Paper is uncountable as a material (I need some paper), but a paper is an essay. Time is uncountable as an amount (we have little time), but times means occasions (I called three times). Food is usually uncountable, but foods means kinds of food, as in unhealthy foods. The context tells you which one you need.
What is the plural of criterion and phenomenon?
The plural of criterion is criteria, and the plural of phenomenon is phenomena. Both words come from Greek, so they do not add -s. Because criteria and phenomena are already plural, they take plural verbs and cannot follow a or one: the criteria are clear, and one criterion is cost. Never write criterias or phenomenas.
Do singular and plural mistakes lower my TOEFL score?
A single missing -s is a small slip, but these mistakes are easy to see and they tend to repeat, and a repeated pattern makes your English look less controlled. They count inside Writing and Speaking, the two sections where grammar is judged. Short singular and plural nouns exercises, such as the levels on this page, train the habit of checking the noun after each counting word.
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