* Noun: When referring to the quality of being important or meaningful.
* Example: "The discovery of the artifact was of great significance to historians."
* Adjective: When describing something as important or meaningful.
* Example: "The significant increase in sales is a good sign for the company."
* Adverb: When modifying a verb, adjective, or other adverb to indicate importance or meaning.
* Example: "The results of the study were significantly different."
To determine the part of speech, look at the context of the sentence and how the word is being used.