Interjections are words or phrases that express strong emotion, and they often stand alone.
Here's why "yuck" is considered an interjection:
* It expresses disgust: "Yuck!" is used to show strong dislike or aversion to something.
* It stands alone: You often use "yuck" by itself, without needing to add other words to complete a sentence.
While it's less common, "yuck" can sometimes function as an adjective if you're describing something as unpleasant or disgusting:
* "That food smells yuck."
However, the most common and natural use of "yuck" is as an interjection.