Put one's foot down:
把脚放下 ×
下定决心 √
例句:
I shall have to put my foot down and stop this nonsense.
我必须采取坚定的态度,制止这一荒谬的事情。
Keep one's feet on the ground:
脚踏实地 √
例句:
Keep your eyes on the stars, and your feet on the ground.
目光高远,脚踏实地。
Stand on one's own feet:
用自己的脚站着 ×
自力更生 √
例句:
I hope you can stand on your own feet.
我希望你能够独立自主。