the
"The" is the most common word in the English language — and also one of the trickiest for learners! It is called a "definite article," and it has a few closely related but distinct uses. Here are the most important ones.
Use 'the' when you and the listener both know exactly which thing you are talking about. Think of it as pointing at something: 'THE one we both know about.' If you say 'a dog barked,' your listener doesn't know which dog. If you say 'the dog barked,' you both already know which dog it is.
everyday language · Modern, universally used