to work extremely hard
非常に一生懸命働く (hijō ni isshōkenmei hataraku)
"He worked his fingers to the bone to build his business."
"彼はビジネスを築くために一生懸命働いた。" (kare wa bijinesu o kizuku tame ni isshōkenmei hataraita)
being planned or developed
something boringly repetitive
to not meet expectations or complete a task successfully
to stop paying attention and mentally drift away
to be lost in thought or imagination
to be successful in life or career
