* Verb: This is the most common use. It describes the action of applying force to move something forward.
* Example: "She is pushing the cart down the aisle."
* Noun: This is less common, but it can refer to the act of pushing itself.
* Example: "The pushing of the button triggered the alarm."
* Gerund: This is when "pushing" acts as a noun, but also retains some verbal characteristics.
* Example: "Pushing a heavy box is hard work."
So, to determine the part of speech, you need to look at how it's used in the specific sentence.