Two Pronunciations of The

The word the has two pronunciations. It is pronounced with a schwa before words that begin with a consonant, and with a high front vowel before words that begin with a vowel. This can be considered a syllable structure process.

The English schwa occurs in many words such as salmon, carrot and lettuce. In these words the schwa occurs between consonants. In the phrases the cat and the dog, the schwa occurs before consonants. However, in the phrases the apple and the orange, the schwa comes before a vowel. To avoid the sequence of a schwa and vowel, the schwa becomes a high front vowel.

The definite article has two pronunciations. One occurs before consonants and the other before vowels. The pronunciation  before consonants occurs in isolation and is unconditioned. It can thus be considered underlying.