...is hard at work.
More like this
Is there a difference between thinking and thinking hard? I mean, thinking is thinking. How can you say if someone is thinking hard or not?
A sergeant in the rangers, on patrol in Afghanistan works hard;
so do nurses, deep sea fishermen, coal miners, sole proprietor restaurant startups.
They guys who painted my house this summer worked outside, 10 hour days, physical labour at half my pay. They worked hard.
"...To see oursels as ithers see us!
It wad frae monie a blunder free us
An foolish notion:"
Yes, everyone has linked the latest, greatest XKCD: