Which article is used with the following words?

first, last, next, same, previous, only

An article is a type of determiner used before a noun, and it defines whether a noun is specific or not. An article can be broadly divided into an indefinite article ("a" and "an") and a definite article ("the"). Definite article "the" is used when talking about a particular thing, with superlatives (the tallest, the shortest, the prettiest), and also with words: first, last, next, same, previous, and only. For example, "the next step", "the first day", "the same book", or "the only pen".