What does the prefix ing mean?

The prefix "ing" doesn't exist as a standalone prefix in the English language. It's actually part of the present participle ending -ing, which is used to form verbs that describe an ongoing action.

Here's a breakdown:

* -ing: This suffix is added to verbs to create the present participle form.

* Present participle: This form of a verb can function as a noun, adjective, or part of a verb phrase.

Examples:

* Singing: The act of singing (noun)

* A singing bird: A bird that is singing (adjective)

* He is singing: He is performing the action of singing (verb phrase)

Therefore, "ing" doesn't have a separate meaning; it's part of the "-ing" suffix that indicates present participle usage.