Before a vowel sound: "thuh" (as in "the apple")
Before a consonant sound: "thee" (as in "the cat")
Examples:
* The apple: "thuh apple"
* The cat: "thee cat"
* The umbrella: "thuh umbrella"
* The book: "thee book"
Exceptions:
There are a few exceptions where "the" is pronounced differently:
* In some proper nouns: "the" is pronounced as "thee" even before a vowel sound, such as "The Hague" (thee hayg).
* In the phrase "the other": "the" is pronounced as "thee" (thee other)
In most cases, you can apply the rule of thumb: vowel sound = "thuh", consonant sound = "thee"