The OU Spelling Pattern: 6 Different Pronunciations (Rules and Patterns)

The two letters OU are one of the most unpredictable spelling patterns in English. Depending on the word, they can produce at least 6 different vowel sounds. That means reading a new word with "ou" is always a gamble, unless you know the patterns.

In this guide, you will learn the 6 main pronunciations of OU, the reliable rules that help you predict the correct sound, and the tricky exceptions you simply need to memorize.

The 6 Sounds of OU: Complete Overview

Before diving into rules, here is a quick reference table of all 6 pronunciations:

Now let's explore each sound with rules, patterns, and practice words.

Sound 1: OU = /aʊ/ (the "out" sound)

This is the most common pronunciation of OU. If you have no other clues, /aʊ/ is your safest guess.

Pattern: OU before most consonants in common words

When OU appears before consonants like nd, nt, th, se, d, t, n in everyday words, it usually sounds like /aʊ/.

More /aʊ/ words: mouse, loud, cloud, round, found, ground, mouth, south, around, count, thousand, hour, our, flour, sour.

Sound 2: OU = /ʌ/ (the "cup" sound)

This pronunciation appears in many common, everyday words. There is no single spelling rule for it; these words must be learned individually.

More /ʌ/ words: cousin, couple, trouble, enough, rough, tough, southern.

Pattern: OU + GH (no T) often = /ʌ/

When OU is followed by GH (but not GHT), it frequently produces /ʌ/: rough /rʌf/, tough /tʌf/, enough /ɪˈnʌf/. However, this same pattern can also produce /oʊ/ (see Sound 4 below), so you need to learn which words fall into which group.

Sound 3: OU = /uː/ (the "food" sound)

Many of these words entered English from French, which explains why OU sounds like /uː/ (similar to the French pronunciation of "ou").

Pattern: OU in French-origin words often = /uː/

More /uː/ words: you, youth, wound (injury), cougar.

Sound 4: OU = /oʊ/ (the "go" sound)

This is a less common pronunciation, but it appears in several important words.

More /oʊ/ words: boulder, although, mold, poultry.

OU + GH contrast: /ʌ/ vs. /oʊ/

Notice that OUGH can be either /ʌf/ or /oʊ/:

Sound 5: OU = /ʊ/ (the "book" sound)

Pattern: COULD, SHOULD, WOULD (memorize these 3)

The easiest pattern here is to simply memorize the three modal verbs. The L is silent in all three.

Sound 6: OU = /ɔː/ (the "thought" sound)

Pattern: OU + GHT = always /ɔː/

This is one of the most reliable rules in English spelling. When OU is followed by GHT, the pronunciation is always /ɔː/ and the GH is silent:

Complete OUGHT list: bought, brought, thought, fought, sought, ought. All pronounced /ɔːt/.

Also /ɔː/: four, pour, court, course, source, cough (/kɔːf/).

The OUR Problem: 3 Different Sounds

The combination OUR is especially tricky because it varies widely:

The OUGH Challenge: The Hardest Pattern in English

The combination OUGH might be the single most difficult spelling pattern in the English language. It can produce at least 7 different sounds:

This is why OUGH is legendary among English learners!

The "Wound" Problem: Same Spelling, Different Sounds

The word wound has two completely different pronunciations depending on meaning:

"The soldier's wound (/wuːnd/) was caused when the wire wound (/waʊnd/) around his arm."

Quick Reference: Decision Rules

Use these rules to make educated guesses about unfamiliar words:

1. OU + GHT? Always /ɔː/ (bought, thought, fought).
2. COULD, SHOULD, WOULD? Always /ʊ/ (memorize these three).
3. OU + GH (no T)? Either /ʌf/ (rough, tough) or /oʊ/ (though, dough).
4. Word looks French? Probably /uː/ (soup, group, route).
5. OUR? Check context: /aʊr/ (hour), /ɔːr/ (four), or /ʊr/ (tour).
6. Default guess: /aʊ/ (the most common OU sound).

Practice Exercise: What Sound Does OU Make?

Test yourself with these words. Read each one aloud, then check the answer:

Related Resources

• Practice Vowel Sounds
• Silent Letters in English
• Practice Consonant Sounds