Many English words change their final consonant — and sometimes their vowel — depending on whether they are a noun or a verb. Use (the noun) ends in /s/; use (the verb) ends in /z/. This is not random. It is a systematic pattern called voicing alternation.
The Rule
- Nouns and adjectives tend to end with a voiceless consonant: /s/, /f/, /θ/.
- Verbs tend to end with the voiced counterpart: /z/, /v/, /ð/.
Practice Pairs
Pattern Table
| Noun / Adjective | Verb | Change |
|---|---|---|
| use /juːs/ | use /juːz/ | s → z |
| house /haʊs/ | house /haʊz/ | s → z |
| close /kloʊs/ | close /kloʊz/ | s → z |
| advice /ədˈvaɪs/ | advise /ədˈvaɪz/ | c → s + /s/ → /z/ |
| excuse /ɪkˈskjuːs/ | excuse /ɪkˈskjuːz/ | s → z |
| breath /brɛθ/ | breathe /briːð/ | θ → ð + vowel |
| belief /bɪˈliːf/ | believe /bɪˈliːv/ | f → v |
| half /hæf/ | halve /hæv/ | f → v |
More Pairs to Practice
- teeth /tiːθ/ → teethe /tiːð/
- bath /bæθ/ → bathe /beɪð/
- proof /pruːf/ → prove /pruːv/
- relief /rɪˈliːf/ → relieve /rɪˈliːv/
- grief /ɡriːf/ → grieve /ɡriːv/
- shelf /ʃɛlf/ → shelve /ʃɛlv/
Why Does This Happen?
It is a fossil of Old English. Verbs historically took a suffix with a voiced sound that shifted the final consonant; over centuries the suffix disappeared, but the voicing survived. The result: two words with the same spelling but different pronunciations.
Related Rule: Stress Shift
Two-syllable noun-verb pairs often shift stress: nouns stress syllable 1, verbs stress syllable 2.
- RECord (n) → reCORD (v)
- PROduce (n) → proDUCE (v)
- PRESent (n) → preSENT (v)
Exceptions
- abuse: noun /əˈbjuːs/, verb /əˈbjuːz/ — follows the rule.
- address: both noun and verb /ədˈrɛs/ in American English — no change.
- practice (n) and practise (v) are spelled differently in British English, pronounced the same.
Key Takeaways
- Nouns often end voiceless (/s/, /f/, /θ/); verbs often end voiced (/z/, /v/, /ð/).
- Sometimes the spelling also changes (advice/advise, belief/believe).
- Two-syllable pairs may also shift stress (RECord/reCORD).
- Recognizing this pattern helps distinguish meaning by sound.