One of the trickiest aspects of English pronunciation is how words in the same family can have completely different stress patterns and vowel sounds. Understanding these shifts will help you sound more natural and guess the pronunciation of new words.
What Are Word Families?
Word families are groups of words that share a common root. As suffixes are added, the pronunciation often changes dramatically—especially stress placement and vowel quality.
The Photo Family
Watch how stress moves and vowels change:
Pattern: Notice how "photo" starts with stress on PHO-, but "photographer" has stress on -TOG-. The first vowel changes from /oʊ/ to /ə/.
The Nation Family
Pattern: The vowel in "nation" /eɪ/ becomes /æ/ in "national" and related words.
The Electric Family
The Know Family
Pattern: The long /oʊ/ in "know" becomes short /ɑː/ in "knowledge."
The Sign Family
Pattern: Silent G in "sign" /saɪn/ but pronounced G in "signal" /ˈsɪɡnəl/. The vowel also changes from /aɪ/ to /ɪ/.
The Pronounce Family
Pattern: Note that "pronunciation" does NOT have "pronounce" in it—it's pro-NUN-ci-a-tion, not "pronounciation."
The Medicine Family
The Long/Short Vowel Pattern
Many word families show this pattern—a long vowel in the base word becomes short when suffixes are added:
| Base Word | Derived Word | Vowel Change |
|---|---|---|
| nature /ˈneɪtʃər/ | natural /ˈnætʃərəl/ | /eɪ/ → /æ/ |
| sane /seɪn/ | sanity /ˈsænɪti/ | /eɪ/ → /æ/ |
| please /pliːz/ | pleasant /ˈplezənt/ | /iː/ → /e/ |
| wide /waɪd/ | width /wɪdθ/ | /aɪ/ → /ɪ/ |
| crime /kraɪm/ | criminal /ˈkrɪmɪnəl/ | /aɪ/ → /ɪ/ |
| divide /dɪˈvaɪd/ | division /dɪˈvɪʒən/ | /aɪ/ → /ɪ/ |
Stress-Attracting Suffixes
Some suffixes "attract" stress to the syllable before them:
- -tion/-sion: educátion, divísion
- -ity: electrícity, natíonality
- -ic: electríc, phonétic
- -ical: histórical, políitical
Practice Exercise
Say these word families aloud, paying attention to where the stress falls:
- econOMy → ecoNOMic → ecoNOMical
- PHOto → phoTOGrapher → photoGRAPHic
- poLItics → poLItical → poliTIcian
- PSYchology → psychoLOgical → psyCHOlogist