Quick answer: French has closed and open o qualities. Keep both short and steady; closed o is higher and more rounded, while open o uses a slightly lower jaw.
Five-minute practice
Try this routine aloud
Say eau as a short closed vowel.
Say porte with a more open vowel.
Alternate beau and bord.
Keep the lips rounded.
Use one word in a phrase.
Watch, listen, then practise · 1 minute 33 seconds
French Open vs Closed O: Listen to /ɔ/ and /o/
Hear /o/ and /ɔ/. Then test your listening. Listen, pause to practise and check what you heard.
The terms “open” and “closed” here describe vowel quality, not whether your lips are sealed. /o/ is the closer rounded vowel; /ɔ/ is more open. Listen to two models before deciding how much to move your jaw, since the difference is not an instruction to exaggerate the mouth position.
Use eau and or as example words to locate the two targets. They are not a minimal pair because their consonant structure differs. Once you can hear the vowel difference, try a matched contrast such as paume and pomme in a variety that distinguishes them.
Spelling and syllable structure offer clues, but the distribution varies by word and accent. Check the reference for the word you actually need. The vowel trainer lets you replay /o/ and /ɔ/ without turning the exercise into an automated assessment.
Try six listening questions for closed and open o. The matching /o/–/ɔ/ pair is selected before you start. Listen to each isolated synthetic clip, choose the vowel, then review its IPA and mouth cue.
Mouth position and airflow
For closed o, round the lips and keep the jaw higher. For open o, relax the jaw slightly while keeping the vowel steady.
Learn the three core French nasal vowel contrasts /ɑ̃/, /ɔ̃/, and /ɛ̃/: spelling patterns, mouth cues, minimal pairs, exceptions, and a five-minute routine.