What part of speech is substantial?

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

* Adjective: This is the most common use. It describes something that is large, important, or of considerable value.

* Example: "They made a substantial donation to the charity."

* Noun: It can refer to something that is essential or fundamental.

* Example: "The substantial part of the argument was ignored."

* Adverb: It can modify a verb, adjective, or other adverb, meaning "to a significant degree."

* Example: "The project was substantially complete."

So, to determine the part of speech, you need to look at its function in the sentence.