làm việc quần quật 
to work hard and without rest, toil [ làm ] : to do, work, make, function as, serve; to cause something to happen
[ việc ] : affair, thing, work, job, matter, business, idea
[ quần ] : trousers, pants
[ quật ] : to whip, flog, beat
Most Common Compounds Set 1:
Most Common Compounds Set 2 :