See the difference
For "bad" the tongue sits low and flat at the front of your mouth, and your jaw is wide open. For "bed" the tongue rises about halfway.
Try it
- Say "eh" as in "bed". Hold it.
- Open your jaw slowly, keeping the tongue forward, until you can fit two fingers between your teeth.
- The sound should turn into the vowel in "bad", and your lips spread a little.
- Now go back and forth. Your jaw should move visibly each time.
Pairs to practice
- bagbeg
- sadsaid
- hadhead
- patpet
- batbet
- satset
We left out pairs like "man" and "men" or "and" and "end". In General American, the vowel in "bad" rises to about the height of the one in "bed" before m, n and ng, so the difference you're practicing is gone in those words.
Does practice work?
English vowels do respond to training in Mandarin speakers. Thomson (2012) trained 26 of them on ten vowels over eight short sessions, and the gains held for a month. Wang and Munro (2004) saw gains hold for three months. Both trained the ear by having people listen to many voices and identify the vowel, so listening helps as well as speaking.
What to do next
Reading how a sound is made helps, but a page can't tell you whether your own tongue got there. In Language Boss, every sound you say in a scene is scored after the call, and you're told what it came out as. X-ray Mouth draws the tongue and lips over your own cheek while you say a phrase to the camera, so you can see what to change. X-ray Mouth is free.
Questions
Why does the mirror help with vowels?
Vowels have no contact point, so you can't feel them the way you can feel your teeth on your lip for v. Your jaw is the part you can see. For "bad" and "bed", the jaw movement gets you most of the way.
Is it the same in British English?
The two vowels are separate in both, though British speakers tend to make the vowel in "bad" lower. The instructions here work for either.
