British English vowel contrast: /ʊ/ as in "pull" · /u:/ as in "pool"
Listen to the two examples.
Listen to the word and decide which vowel sound you hear.
The word is hidden until you answer.
Which sound do you hear?
/ʊ/ is a short vowel sound, as in pull, full, wood.
/u:/ is a long vowel sound, as in pool, fool, wooed.
Concentrate on the vowel sound itself rather than on the spelling.