A1 used before nouns to refer to particular things or people that have already been talked about or are already known or that are in a situation where it is clear what is happening:

A1 used before some nouns that refer to place when you want to mention that type of place, without showing exactly which example of the place you mean:

A1 used before noun phrases in which the range of meaning of the noun is limited in some way:

A1 used to refer to things or people when only one exists at any one time:

A2 used before superlatives and other words, such as "first" or "only" or numbers showing something's position in a list, to refer to only one thing or person:

used to say that the particular person or thing being mentioned is the best, most famous, etc. In this use, "the" is usually given strong pronunciation:

used before some adjectives to turn the adjectives into nouns that refer to one particular person or thing described by the adjective:

used before some adjectives to turn the adjectives into nouns that refer to people or things in general that can be described by the adjective:

used before a singular noun to refer to all the things or people represented by that noun:

used before a family name to refer to two people who are married or to a whole family:

used before some nouns referring to musical instruments or dances to mean the type of instrument or dance in general:

used before a noun to represent the activity connected with that noun:

B2 used before numbers that refer to periods of ten years:

B2 used before each of two comparative adjectives or adverbs when you want to show how one amount gets bigger or smaller in relation to the other:

used before comparative adjectives or adverbs when you want to show that someone or something has become more or less of a particular state:

used for emphasis when you are expressing a strong opinion about someone or something:

B1 used instead of a possessive adjective such as your, her, or my:

enough:

each; every: