Hey a,

Quick question: what's the most common vowel sound in English?

It's not /æ/, /e/, or /ɒ/, it's the schwa /ə/, that quick, relaxed "uh" sound tucked into words like "about," "chocolate," and "computer." Most learners have never been taught it directly, but once you can hear and use it, both your speaking and your listening improve fast.

There's also a free PDF with all the examples, rules, and a short practice story from the lesson, the link's in the video description.