How do you pronounce "the"?

Hi, hopefully someone can help me. I'm trying to figure how to pronounce "the".

As I understand it, you can say it in two ways:

"the ocean" - something like "thee"
"the car" - something not using double e.

Hopefully this makes sense. Is there a rule on it's pronunciation?

Thanks in advance.

Fran.

[Horsa]

We use the pronunciation 'thee' when the next word begins with a vowel sound. Just like the use of a/an.

So The ('thee') apple, engine, island, orange, undercarriage, etc.

But

The (short pronunciation) region, terminator, book, union (begins with a consonant sound), etc.

[ernesta]

I hope I can help you with my answer.
The pronunciation of THE is different depending on the initial letter of the following word. I need the IPA (International Phonetic Alphabet) symbols to express the right sounds.
For instance:
THE CAR = you will pronounce ðə (voiced dental fricative+mid central unrounded vowel), because the initial letter is a consonant.
THE APPLE = you will pronounce ði (voiced dental fricative+ close front unrounded vowel), because the initial letter is a vowel.
And if you want to emphasize this article, you will pronounce ði: (long vowel).

[fungicord]

It's important to understand that most native English speakers aren't aware of the vowel/consonant rule for the pronunciation of "the." People say "thee" because it's more easily spoken that way before a vowel. I commonly hear American speakers using the wrong one. It's most common when a person is pausing because they're not sure what word they plan to use next. This is partly because the filler/stall word "um" begins with a vowel sound. For example, a person says, "I'm going out to (thee) um... garage." The person might just as easily say, "I'm going out to (thee) ... garage." The reason is that the speaker is thinking "um" in their mind, but they're not saying it aloud because they want to sound more sophisticated.

Because the vowel/consonant rule isn't well-known, it's common among nerds/geeks to say (thee) more often than it should be used. If an English speaker is pretending to be nerdy, they will often use (thee) excessively and stress it very heavily. An example of an English speaker mocking a nerd would be, "(Thee) reagent must be added to (thee) formula to cast (thee) magic missile spell against (thee) red dragon." This type of nerd/geek imitation happens a lot in children's cartoons. It's important for anyone who plans to live in an English-speaking society to master the correct pronunciations of "the" so they don't accidentally sound like a nerd.