To (/tu:/) is an English word that can function as a preposition or a particle. It is the third most common word in English, after the, and various inflections of the verb be. The prepositional and particular usage are fundamentally related.
As a preposition, its primary meaning is as a preposition of direction meaning "in the direction of". For example, "We’re going to the swimming pool later". To can serve as the head of a preposition phrase, known as a to phrase.