用盡心機

to tax one's ingenuity

to use / to employ / to have to / to eat or drink / expense or outlay / usefulness / hence / therefore

to exhaust / to use up completely

to use up / to exhaust / to end / to finish / to the utmost / exhausted / finished / to the limit (of sth) / all / entirely

with all of one's heart

heart / mind / intention / center / core / CL:顆|颗[ke1],個|个[ge4]

thinking / scheme

(bound form) machine; mechanism / (bound form) aircraft / (bound form) an opportunity / (bound form) crucial point; pivot / (bound form) quick-witted; flexible / (bound form) organic