The Pronunciation of Five Words With The Trap-Bath Split

The trap-bath split refers to a historical development which took place in England. Speakers with the split pronounce the word trap with a front vowel and bath with a back vowel. However, speakers who lack the split pronounce the two words with the same vowel. In parts of southwestern England, the words trap and bath are pronounced with different vowels, but the different is not qualitative. It is quantitative because the vowel in trap is a short front vowel and the vowel in bath is a long front vowel.

The trap-bath split divided England into two parts. Most speakers in the north lack the split, and most speakers in the south have the split. In the USA, almost all speakers lack the split. 

In all of England, there are five words which are pronounced with the low back vowel. They are banana, calf, can't, half, and rather. The word banana is pronounced with the back vowel in the stressed second syllable. In the other syllables, the schwa is used.

In the USA, the five words are pronounced with the low front vowel. However, a number of Americans use the low back vowel in the word rather. Regardless, the use of the back vowel is definitely less common.

The difference in the pronunciation of the five words in England and the USA may reflect that the trap-bath split became common in England after the colonial period. American English often preserves features that are no longer common in England. One example is the rhotic accent that is more common in the English of the USA than in the English of England.

In England the words banana, calf, can't, half and rather are all pronounced the same. They all have the low back vowel. In the USA, they are pronounced with the low front vowel, but a number of American English speakers use the low back vowel in the word rather. It may be that the low front vowel in those words reflects an older pronunciation of English.