* Determiners: This is the most common classification. "All" acts as a determiner when it modifies a noun, indicating quantity or entirety. For example: "All the students passed the exam."
* Pronoun: In some cases, "all" can function as a pronoun, representing a group of people or things. For example: "All are welcome."
* Adjective: When "all" describes a noun, it can also be considered an adjective. For example: "The room was all white."
Ultimately, the specific word type of "all" depends on its usage within a sentence.