Which is the only noun that ends with ing?

This is a bit of a trick question! There isn't actually a noun that ends with "ing" in the English language.

The "-ing" ending is typically associated with verbs in the present participle form (e.g., "running," "singing," "walking"). However, some words that end with "ing" can be used as nouns, but only when they're referring to the act of doing something (e.g., "swimming" as a sport).

Let me know if you'd like to explore more about parts of speech!