Lesson · Nouns and Articles · One and more than one

One Noun, Two Nouns

A plural is the form of a noun that means more than one. On the 1,887 nouns in the printed list, a rule with three parts gives the plural the dictionary, a book that lists the words of a language, has for 1,866 of them. This lesson states the rule, reads the 21 nouns it misses, and tries three ways of improving it. Two of the three make it worse.

Open the interactive lesson Practice

cat, day add -s box, church add -es after a hiss city, baby -y becomes -ies right on 1866 of 1887 98.9% it misses 21; 9 are old plurals: men, women, feet, teeth, children

The plural rule on 1,887 nouns

Core ideas

What this lesson establishes

Three ideas. The last one is about how to improve a rule.

A plural rule has three parts, and the parts are about the end of the word

Add -s. After a hiss, a sound like the end of bus or dish, written s, sh, ch, x or z, add -es, so box becomes boxes and church becomes churches. After a consonant, any letter that is not a, e, i, o or u, and y, change the y to ies, so city becomes cities. After a vowel, one of those five letters, and y the first part is enough: day becomes days.

The words it misses are not random

Of 1,887 nouns the rule is right for 1,866 and wrong for 21. Nine of the 21 are old plural forms that no ending makes (man, men; child, children), five end in f or fe and change it to v (wife, wives), five come from Greek (crisis, crises), and two are single cases: potato and stomach. Each group has a reason, and each group is short enough to learn.

A new rule has to be scored on the whole list, not on the words you thought of

It is easy to think of a rule that fixes some words. The lab adds three of them one at a time. Two fix a few words and break more. The one that helps is the one that names its endings exactly. The count shows that; the feeling that a rule is good does not.

The material

The 21 nouns the rule with three parts misses

Switch the lab to the first rule and read the table of misses. They fall into five groups.

Every noun that you can count has two forms: one for one thing and one for more than one. The second is called the plural. You have met the main rule for making it: it is the -s rule of Tense Tables, which put -s on a verb after he, she and it. This lesson runs the same rule on nouns and counts how often it is right.

The lab holds 1,887 nouns from the word list, each with the plural forms the dictionary confirms for it. The rule makes a form for each. If the form is one the dictionary has, the rule is right for that noun. The rule has three parts: add -s; add -es after a hiss; change a consonant and y to ies.

How often the three parts are right

Counted on this page, the rule is right for 1,866 of the 1,887 nouns, which is 98.9%. That is a rule you can use with no further thought, and the table at the bottom of the lab prints the 21 nouns where it is wrong.

Reading the 21

Nine are old plural forms that no ending makes. Seven of them change the vowel in the middle of the word: man, woman, foot, tooth, mouse, chairman and gentleman. Child adds an ending of its own, children, and die has dice. Five end in f or fe and take ves: half, life, self, shelf, wife. Five come from Greek: analysis, crisis, emphasis, hypothesis and phenomenon. The last two are single cases. Potato takes -es after an o. Stomach ends in the letters ch, but they say k, so the hiss part gives the wrong form.

That is five reasons, and the longest list under any of them has nine words. The rule plus these five short lists is enough for every noun in the table.

Three ways to improve it

An obvious next step is to add a rule for each group. The lab lets you add three, one at a time, and score the result on the same 1,887 nouns. Each one comes from a good reason. Each one fits the nouns that made you think of it.

Add the -oes part for a consonant and o, and the score falls by two, to 1,864. It gains potato. It loses photo, piano and pro. Add to that the idea that f or fe becomes ves, and the score falls to 1,861. It gains half, life, self, shelf and wife, and loses belief, brief, chief, golf, proof, relief, roof and safe.

The version that helps

The third change keeps the -oes part and replaces the idea about f with a narrow one: use ves only after -lf, -ife, -eaf or -olf. That raises the score to 1,868 of 1,887, which is 99.0%. It still loses photo, piano and pro, and it breaks golf, which ends in -lf but is golfs. It fixes the five f nouns. Leaf and wolf, which two of its endings are written for, are not in the list at all. The size of the endings it names is what makes the difference.

The gain is two nouns over the rule with three parts, and the cost is a rule with a list of endings inside it. For most readers the better choice is the plain rule and the short lists.

What the table cannot tell you

The dictionary says which forms exist, not which one is common. Where it has two forms, the lab counts the rule as right if it makes either one. The words come from a list of two thousand eight hundred common words, so rare nouns, which have more irregular plural forms, are not in the table.

Interactive

The plural rule, scored on every noun in the list

Each word's form is made by the rule on the page and checked against a dictionary

the rule—

the rule is right—

share—

it misses—

the words it misses—

nouns with no plural—

of the nouns that are only nouns—

Method

Making the plural of a noun in front of you

Four questions, in this order.

Is it one of the old plural forms?

Man, woman, child, foot, tooth, mouse and the words built on them, such as gentleman. If it is, you know the plural already, and no rule is needed.

Does it end in a hiss?

Look for s, sh, ch, x or z. If so, add -es. Say the word: church ends in the same sound it starts with, so it takes -es, but stomach ends in a k sound and takes -s.

Does it end in a consonant and y?

Then change y to ies. A vowel before the y (boy, day, key) keeps it, and you add -s.

Otherwise add -s, and check the short lists

That covers almost every noun. The lists to learn are the old plural forms, the f words and a few from Greek. Add potato to them, and keep photo and piano out of the -oes group.

Check yourself

Score 0 / 0

Choose the answer you can justify.

Potato and photo: the rule that gains one word and loses three

A natural fix is to add a fourth part: after a consonant and o, add -es. It works for potato. Choose the second rule in the lab and read its misses.

potato potatoes right with the new part photo photos wrong with the new part piano pianos wrong with the new part pro pros wrong with the new part 1866 of 1887 becomes 1864 of 1887

The new part gains one word and loses three, so the score goes down by two. Radio, video and studio are not touched, because a vowel stands before the o. The spelling cannot tell potato from photo. One of them is short for something else, and nothing in the letters says so.

Common mistakes

Writing f becomes ves as the ruleIt fits half, life, self, shelf and wife. It breaks belief, brief, chief, proof, relief, roof and safe, and golf too. Added to the rule that already has the -oes part, it fixes five nouns and breaks eight, and the score goes from 1864 to 1861 of 1887. A narrower rule that names only the endings -lf, -ife, -eaf and -olf fixes the five and adds one miss, golf. It is the best of the four.

Adding -es to every noun that ends in oOnly some do. Counted on the list, the -oes part loses more than it gains. Learn potato as one noun, and hero as a noun the dictionary spells both ways.

Treating an old plural as a mistake in the ruleMen, women, feet and teeth are very old forms that came before the -s rule. The rule did not fail on them; they were never made by it. They are nine nouns in this list, and learning nine is less work than building a rule that covers them.

Check your understanding

✓

Finish when you can write the plural of a noun you have not seen before, and say which rule you used.

You should be able to apply the three parts of the plural rule in order, read its score on the printed list of nouns, name the kinds of noun it misses, and show with the lab why two extra rules make the score worse and a third, narrower one makes it a little better.

Note: Where the dictionary has two plural forms for a noun, the rule counts as right if it makes either one. That is why hero (heroes or heros) and index are not in the list of misses, and why person is not: its plural can be persons, as well as people. Knife is a harder case. The dictionary confirms knifes because it is a form of the verb (he knifes), so the rule's form counts as right, though the plural you should write is knives. The lab reads spellings, not meanings, and it says so under its numbers. It prints every plural the dictionary has next to the rule's, so you can check each decision.