In English grammar, the definite article "the" is used to refer to specific or unique entities or objects. It is used with distinctive structures to indicate that the noun being referred to is specific and known to both the speaker and the listener.
Used with superlative forms: When comparing multiple items and identifying the most extreme or highest degree of something, "the" is used. For example, "the tallest building," "the fastest car," or "the biggest city."
Used with unique nouns: When referring to a specific entity that is one-of-a-kind or clearly identified, "the" is used. For example, "the sun," "the moon," or "the President."
Used with specific nouns: When referring to particular objects or things, "the" is used to indicate specificity. For example, "the book on the table," "the house next door," "the restaurant we went to."
Used with certain structures: "The" is used in certain grammatical structures like "the + adjective" to form specific noun phrases. For example, "the rich," "the poor," or "the elderly."
It important to note that the usage of "the" depends on the context and the specific language rules.