What is the part of speech for down?

"Down" can be several parts of speech, depending on how it's used in a sentence:

* Preposition: "The ball rolled down the hill."

* Adverb: "He looked down at the ground."

* Adjective: "The down payment was significant."

* Noun: "He felt a sense of down." (meaning sadness or depression)

To determine the part of speech for "down," you need to look at how it's used in the context of the sentence.