Plural s or es: how to choose
In short
Most nouns add s to make a plural: cats, books, trees. Add es after words that end in s, x, z, ch or sh, as in buses, boxes, buzzes, lunches and dishes. The clue is sound: if the plural adds a syllable you can hear, it is usually es.
When do you add es?
Add es when the base word ends in s, x, z, ch or sh. These are hissing and hushing sounds, and adding another /s/ right after them would be hard to say and hard to hear. So English adds a short vowel sound, spelled e, and the plural gets an extra syllable: box becomes box-es, dish becomes dish-es.
| Base ends in | Plural ending | Examples |
|---|---|---|
| s, ss | es | bus, buses; dress, dresses |
| x | es | box, boxes; fox, foxes |
| z, zz | es | buzz, buzzes; quiz, quizzes |
| ch | es | lunch, lunches; bench, benches |
| sh | es | dish, dishes; brush, brushes |
| Most other letters | s | cat, cats; book, books; tree, trees |
How does sound help students choose?
Have students say the plural and count syllables. Cat has one syllable, and cats still has one. Box has one, but boxes has two. If the plural adds a syllable, it almost always takes es. This sound test is easy for young students and works even before they know which letters trigger es.
- Teacher
- Say lunch. Now say more than one.
- Student
- Lunches.
- Teacher
- Clap it.
- Student
- Lunch-es. Two claps.
- Teacher
- An extra beat means es.
The test also catches a common error. Students who write lunchs have heard the extra syllable but not written it. Asking them to clap the word usually fixes it.
What about words ending in y?
For nouns ending in a consonant plus y, change y to i and add es: baby, babies; city, cities; party, parties. For nouns ending in a vowel plus y, just add s: toy, toys; day, days; monkey, monkeys. This follows the change y to i rule, which students may learn at the same time or soon after.
What about words ending in f and o?
Some nouns ending in f or fe change to ves: leaf, leaves; knife, knives; wolf, wolves; half, halves. Others just add s: roof, roofs; chief, chiefs. There is no simple rule, so the ves words are best learned as a list. Listening helps, though. If the plural sounds like /vz/, it is spelled ves.
Nouns ending in o are also mixed. Potato, tomato, hero and echo add es. Piano, photo, radio and zoo add s. Many of the s words are shortened forms or borrowed words. Again, the list approach works best, and these are usually taught in third grade or later.
| Pattern | Examples |
|---|---|
| f or fe to ves | leaf, leaves; knife, knives; wolf, wolves |
| o plus es | potato, potatoes; hero, heroes; echo, echoes |
| o plus s | piano, pianos; photo, photos; radio, radios |
| Irregular | child, children; mouse, mice; tooth, teeth |
How do you teach plurals?
- Start with s plurals on short words students know: cats, dogs, cups.
- Introduce es with words like bus, box, buzz, lunch and dish. Clap the syllables.
- Sort words into s and es piles by sound and by ending.
- Dictate singular words and have students write the plural.
- Add y words once students know s and es well.
- Teach f, o and irregular plurals as short lists later on.
Keep the first lessons to s and es. That alone covers most plurals students write in kindergarten and first grade. The y, f and o patterns can wait until the basics are automatic.
Does the same rule work for verbs?
Yes. Verbs that take s in the present tense follow the same pattern: she runs, he jumps, but she washes, he fixes, it buzzes. The sound test works the same way. A student who knows the plural rule can apply it directly to verbs, which saves a separate lesson.
The ending s also has two sounds, /s/ in cats and /z/ in dogs, depending on the sound before it. That rarely causes spelling trouble, since both are spelled s, but it explains why some students write dogz. Telling them s can say /z/ at the end of a word usually clears it up.
When should plurals be taught?
S plurals come in kindergarten, as soon as students write CVC words. Es comes in first grade, usually after digraphs, since ch and sh trigger it. Y plurals follow the change y to i rule in second grade. F, o and irregular plurals belong in second and third grade, as they come up in reading and writing.
How do irregular plurals fit in?
A small group of very common nouns makes plurals in old ways that do not use s at all. Child becomes children, man becomes men, mouse becomes mice, foot becomes feet, and tooth becomes teeth. A few, like sheep, deer and fish, stay the same. These are survivors from an older form of English, and there are not many of them.
Students usually know most of these from speech long before they write them, so the spelling is the only new part. Teach them as a short list in second grade, with a picture or a quick sketch for each, and add new ones as they come up in reading. Young writers who produce mouses or foots are applying the regular rule logically, which is worth saying before you show the irregular form.
For older students, irregular plurals in science words, like cactus and cacti or fungus and fungi, can wait until they appear in content reading. Explain that these come from Latin and follow Latin patterns, and that both the Latin and the regular English plurals are often accepted.