Choose the correct word to complete the gym buddy's text message.

If you want to beat the reigning champion at the arm-wrestling contest, you will need to push yourself _____ than you did yesterday!

The correct answer is harder.

We need an adverb to modify the verb push. The word "hard" is an irregular adverb that looks exactly the same as its adjective form. (Note: "Hardly" is a completely different adverb meaning "barely"). Because we are comparing today's effort to yesterday's effort using "than," we add -er to make the comparative form harder.