"The job is hard."
Translation:El trabajo es duro.
No it cannot. DL is trying to make that connection for english speakers because we associate physical things with feelings. We understand and use that hard is associated with something literally be hard. But we also say that hard is complicated because the thing in which we are doing is a block and a mental solid wall to push through. Spanish doesn't work that way unfortunately, and you must say difícil. But DL is DL
Jonathan is correct. At least in Mexico, duro is only used to describe objects that are physically hard, like a diamond.
No, "work" as a noun is always masculine meaning it uses "el" for "the" and ends in an "o".
Although "trabaja" is a word, but it's a verb meaning He/She works.
"La trabaja" is incorrect.