Two sounds close enough to trade places: the “w” of water and the “v” of van. Swap one for the other and a different word comes out — this page is how to keep them apart, in both directions.
Keep your teeth completely off your lip; round both lips into a small circle and glide.
“No teeth! The teeth are banned from this sound! Round the lips like whistling at a beautiful plate of pasta.”Nunzio, when he hears it
Un-round your lips and touch your top teeth to your bottom lip, letting voiced air buzz through.
“Too much kissing! Un-pucker, bello. Top teeth rest on the bottom lip, gentle, and buzz like a scooter.”Nunzio, when he hears it
You cannot hear your own swap. That is the whole problem.
Nunzio records you reading a sentence, scores every sound in it on your phone — nothing is uploaded — and tells you which of these two actually came out. Nunzio — Accent Coach is coming to the App Store and Google Play.