In English, the final –s or –es at the end of words can be pronounced in three different ways: /s/, /z/, and /ɪz/ (sometimes written as /əz/). Although the spelling looks simple, the pronunciation changes depending on the final sound of the word before the –s. Understanding these rules helps with speaking clearly and listening accurately, especially when studying English as a second language.
1. The /s/ sound (voiceless S)
The final –s is pronounced /s/ when the word ends in a voiceless sound.
Voiceless sounds are sounds made without vibrating the vocal cords.
Voiceless final consonants:
- /p/
- /t/
- /k/
- /f/
- /θ/ (th as in “bath”)
Examples:
- cap → caps /kæps/
- cat → cats /kæts/
- book → books /bʊks/
- leaf → leafs (or leaves) but “leafs” is pronounced /liːfs/
- bath → baths /bæθs/
Here, the final sound before –s controls the pronunciation. For example, “cat” ends in /t/, a voiceless sound, so adding –s gives /s/. Saying cats with a /z/ sound would sound unnatural to native speakers.
A helpful tip: when the last sound feels “sharp” or “quick,” like /p/ or /k/, the ending is usually /s/.
2. The /z/ sound (voiced Z)
The final –s is pronounced /z/ when the word ends in a voiced sound.
Voiced sounds are sounds made with the vocal cords vibrating.
Voiced sounds include:
- All vowels (a, e, i, o, u)
- Voiced consonants:
b, d, g, v, ð, m, n, ŋ, l, r, z, ʒ, dʒ
Examples:
- boy → boys /bɔɪz/
- tree → trees /triːz/
- bag → bags /bægz/
- dog → dogs /dɔːgz/
- glove → gloves /glʌvz/
- fan → fans /fænz/
- car → cars /kɑːrz/
- name → names /neɪmz/
In these cases, the –s becomes /z/ because it follows a sound with vibration. For example, in dog, the final /g/ is voiced, so dogs uses a /z/ sound.
A good way to check: place your fingers on your throat. If you feel vibration when pronouncing the last sound of the base word, then the plural or verb ending will likely use /z/.
3. The /ɪz/ or /əz/ sound (extra syllable)
The final –es is pronounced /ɪz/ when the word ends with a sibilant sound.
Sibilants are sounds that create a hissing or buzzing effect. Because these sounds already end with something close to an “s,” English adds a short vowel to make pronunciation easier. This means the plural form has an extra syllable.
Sibilant sounds:
- /s/
- /z/
- /ʃ/ (sh)
- /ʒ/ (as in “beige”)
- /tʃ/ (ch)
- /dʒ/ (j)
Examples:
- bus → buses /ˈbʌsɪz/
- kiss → kisses /ˈkɪsɪz/
- maze → mazes /ˈmeɪzɪz/
- brush → brushes /ˈbrʌʃɪz/
- judge → judges /ˈdʒʌdʒɪz/
- church → churches /ˈtʃɜːrtʃɪz/
Notice that each plural has a new syllable: bus-es, brush-es, church-es. The extra vowel /ɪ/ makes the word easier to say.
This rule also applies to verbs in the present tense:
- miss → misses /ˈmɪsɪz/
- watch → watches /ˈwɒtʃɪz/
- judge → judges /ˈdʒʌdʒɪz/
Why the rules exist
English adds these pronunciation patterns to make speaking faster and more natural. When sounds match (voiced with voiced, voiceless with voiceless), they flow smoothly. When sounds clash, English adds a vowel to reduce difficulty.
For example, saying kiss + s as one sound would create sss three times in a row. Adding /ɪ/ breaks the pattern and makes the word easier to pronounce.
Quick Summary
| Ending Sound | Type | Plural/3rd-person –s Sound | Example |
|---|---|---|---|
| Voiceless consonants (p, t, k, f, θ) | No vocal cord vibration | /s/ | cats, books |
| Voiced consonants or vowels | Vocal cord vibration | /z/ | dogs, trees |
| Sibilants (s, z, sh, ch, j) | Hissing/buzzing | /ɪz/ | buses, watches |
Practice Sentences
- The cats /s/ chase the mice.
- My dogs /z/ always wag their tails.
- She washes /ɪz/ the dishes every night.
- He runs /z/ fast when it rains /z/.
- The teachers /z/ visit the churches /ɪz/ on weekends.
