to use / to employ / to have to / to eat or drink / expense or outlay / usefulness / hence / therefore
用
=
丨
+
月
:
Mnemonic symbol: a first aid kit. Can you see the cross on the container?
用
=
丨
+
月
:
Yu the Great hurt her leg when she slipped in the engine's bathroom. The moon helps her to splint her leg using the bathroom's first aid kit and a dinosaur bone.
meritorious deed or service / achievement / result / service / accomplishment / work (physics)
功
=
力
+
工
:
Gitta Giraffe (gu) practices her Kung Fu skills (功) in front of the engine ((e)ng1) with a sparring robot made out of steel beams (工). The robot is programmed to fight Kung Fu (功), but Gitta Giraffe's Kung Fu is better: she hits the robots power button (力) and turns it off.