Few spellings frustrate learners like OU. The same two letters give us 'out', 'soup', 'touch', 'could', 'four', and 'though', all with different vowels. There is no single rule, but sorting OU into a few sound groups makes it far less scary.
The Rule: Learn OU as Groups
OU maps to at least six sounds. The most common by far is /aʊ/ (like 'ouch'), so make that your first guess. After that, learn the other groups word by word. The four most useful are shown below.
OU = /aʊ/ (the most common, like 'ouch')
OU = /uː/, /ʌ/, and /ʊ/
The Six Groups at a Glance
| Sound | Examples |
|---|---|
| /aʊ/ | out, house, about, mouth, loud |
| /uː/ | soup, group, you, wound, route |
| /ʌ/ | touch, country, young, double, trouble |
| /ʊ/ | could, would, should |
| /ɔː/ | four, pour, court, your |
| /oʊ/ | soul, shoulder, boulder, though |
A Helpful Pattern
One reliable mini-rule: could, would, should always use the short /ʊ/ (like 'book'), never a long sound. And OU + GH is its own maze ('though', 'through', 'thought'), which we cover separately.
Practice Tip
Group ten OU words by ear, then check them. Start with the /aʊ/ default and move outward. For the tricky OUGH family, see our guide to the seven ways to say OUGH.