The Definite Article
If the following word begins with a vowel, we say [ði], and if the following word begins with a consonant, we say [ðə].
“The” vs. No Article
We have listed some examples in the following table. There you can see when we need to use the definite article and when we don't.
Using “the” with Seasons of the Year
The Usage Depends on the Context
In the first sentence we do not use the definite article, in the second we do. The student goes to school for its primary purpose, so we do not use the article.