Vowel Harmony

Level 1

The vowels in a Twi word tend to match in type. Before a root with a tense vowel, such as i or u, a prefix vowel becomes tense too: ɔbaa (woman) but onipa (person).

How It Works

Two sets of vowels. Twi vowels come in pairs: one made with the tongue root pushed forward (tense) and one relaxed. The relaxed set includes ɛ, ɔ and a; the tense set includes i, u and the tense sounds of e and o. See vowels and nasal vowels.

The rule. Inside a word, a prefix takes its vowel type from the vowel that follows it. That is why the same prefix sounds, and often looks, different on different words:

  • Noun prefixes: ɔbaa (woman) and ɔbarima (man), but onipa (person).
  • Subject prefixes: ɔkɔ (he or she goes), but odidi (he or she eats), because di has a tense vowel.
  • The future prefix and the one before it: yɛbɛkɔ (we will go), but yebedi (we will eat), said ye-be-di.

A prefix that never changes. The progressive re- always stays relaxed, so the prefix in front of it stays relaxed too: Ɔredidi (She is eating), even though odidi (She eats) has o. See re- progressive and me- wo- ɔ- yɛ- mo- wɔ-.

Two spelling habits. Harmony always happens in speech, but writers handle verb prefixes in two ways. Many texts spell the sound: odi, obedi, yebedi, edi kan. The Asante Bible and much modern Asante print keep one spelling for each verb prefix: ɔdi, ɔbɛdi, yɛbɛdi, ɛdi kan. You will read both, they are said the same way, and neither is a mistake. Noun prefixes, though, follow the sound in every style: onipa, never ɔnipa. See ɛ- subject prefix and bɛ- future.

Examples (5)

  1. Ɔkɔ sukuu.

    She goes to school.

    Word by Word: She-goes school.

    Kɔ has a relaxed vowel, so the prefix is the relaxed ɔ-.

  2. Odidi wɔ fie.

    He eats at home.

    Word by Word: He-eats at home.

    Didi has a tense i, so the prefix is said o-. Asante print often writes ɔdidi; the sound is the same.

  3. Ɔbaa no yɛ onipa papa.

    The woman is a good person.

    Word by Word: Woman the is person good.

    Both nouns begin with the same prefix: relaxed ɔ- before baa, tense o- before nipa.

  4. Yebedi nkonim.

    We will win.

    Word by Word: We-will-eat victory.

    Before di, both prefixes turn tense: ye-be-. Texts that keep one spelling write Yɛbɛdi nkonim.

  5. Ɔredidi.

    She is eating.

    Word by Word: She-is-eating.

    Re- never changes, so the prefix before it stays ɔ-.

Common Mistakes

  • Using ɔ- on a noun whose root has a tense vowel.

    Ɔnipa no aba.
    Onipa no aba.

    Nipa has a tense i, so its noun prefix is o-. Noun prefixes follow harmony in every spelling style.

How It Connects

Tap a pattern to see what it builds on and what it leads to.

Vowel HarmonyLevel 1

Learn This First

Vowel harmony needs the full vowel set and the subject prefixes whose vowels it changes.