Two little letters, UI, hide behind some of English's most common words, and they refuse to pick one sound. Fruit, build, and guide all share UI, yet no two of them rhyme.
There is real logic here once you sort the words into groups. Two of the sounds come from the vowel itself; the third comes from the U doing the same silent job it does in guess and guitar.
The Rule
UI has three main sounds. It says /uː/ (oo) in the largest group: fruit, juice, suit, cruise, bruise, recruit, nuisance. It says short /ɪ/ in a small but common set: build, built, guilt, guitar, circuit, biscuit. And after G it often just keeps the G hard while the U goes silent, giving /aɪ/ in guide, guise, disguise and /ɪ/ in guild.
See the Pattern in Action
| Sound of UI | Words | How to say it |
|---|---|---|
| /uː/ (oo) | fruit, juice, suit, cruise | froot, joos |
| /ɪ/ (short i) | build, guilt, built | bild, gilt |
| /aɪ/ (long i) | guide, disguise | gyde |
| /uːɪ/ (two vowels) | ruin, intuition, fluid | ROO-in |
Words to Practice
Common Exceptions
When the U and I belong to different syllables, they split into two vowel sounds /uːɪ/ or /uːə/: ruin, fluid, intuition, suicide, genuine, superfluous. So before you pick a sound, check whether UI is one team or two separate vowels meeting at a syllable break.
Quick Tips to Remember
Sort every UI word into three boxes: OO (fruit, juice), short-i (build, guilt), and long-i after G (guide, disguise). Say one word from each box in a row so your ear locks in the contrast, then practice your pronunciation.