Lips
Round your lips loosely into a small oval, pushed slightly forward, like the soft shape in the animation. Loose is the key word. No tight circle.
The vowel in "foot". A short "u" with loose, gentle rounding.
Example words: foot, put, good, book, look

Round your lips loosely into a small oval, pushed slightly forward, like the soft shape in the animation. Loose is the key word. No tight circle.
Back of the tongue rises loosely toward the soft palate. High and back, but relaxed, a notch lower than for long "oo".
Very short. This is the lax partner of long "oo": "full" is quick and loose, "fool" is long with tight rounding.
Record "full, fool, full, fool". The first should be short with barely-rounded lips, the second long with a tight circle. Mirror check: your lips should visibly relax between the two.
Most learners replace this with a long tense "oo", so "full" becomes "fool" and "pull" becomes "pool". If your lips form a tight, effortful circle, you've switched vowels. This sound should feel almost lazy.
🔊 plays the app's native voice. 🎤 records you so you can play it back next to it. Your recording stays in your browser.