The AH in father and the UH in butter can be challenging for non-native English speakers to pronounce. This is because both of these sounds are made in the back of the mouth, and they share similar tongue, lip, and jaw positions. But with a little practice, you should be able to see and hear the differences between these sounds.
The AH /ɑ/ Vowel
The AH vowel is considered a low, back vowel, meaning it is made with the jaw dropped low and the tongue pulled back into the mouth. You may even feel some tension in the tongue as you say this sound because the tongue is low and flat.
If you look at the vowel quadrilateral, you’ll notice the AH vowel is located in the lower right hand corner. It is the lowest and farthest back vowel that is made in American English.
Here are some words with the AH sound. cop, dog, log, bog.
The UH /ʌ/ Vowel
The UH sound is a central vowel. The jaw drops down low, but not as much as it did for the AH sound, and the tongue is more relaxed and neutral in the mouth.
Look at the vowel quadrilateral again to see if you can spot the differences between the locations of the AH and the UH vowels.
Here are some words with the UH sound. bug, lug, cup, dug.
So the differences between the AH in father and the UH in butter are with the jaw and tongue positioning. For the AH sound, the jaw is dropped low, and the tongue is pulled back and flat in the mouth. It also has some tension. But for the UH sound, the jaw is not as low, and the tongue is more neutral and relaxed.
The AH Vowel
The UH Vowel
Thanks for reading, and let me know if you want some help with the AH and the UH vowels.