hard-working
Word family
Synonym discussion
Sense: adjective/1
All four describe someone who puts real effort into work, but the feel is different. "Hard-working" is the everyday, neutral choice — you can use it about a child, a parent, an employee, or a whole community without sounding stiff. "Diligent" is more formal and points to careful, steady attention to detail, often appearing in school reports or job references ("a diligent researcher"). "Industrious" suggests visible, constant activity that produces a lot, and tends to describe whole groups or eras ("an industrious town of weavers"). "Conscientious" focuses less on hours worked and more on a person's sense of duty and care — a conscientious doctor checks every detail because they feel responsible, not just because they are busy. So in casual praise, say "hard-working"; in a written reference, "diligent" or "conscientious" sounds more polished.
Common collocations
Etymology
A compound adjective formed in English from the adverb "hard" (in the sense "with great effort") plus the present participle "working". The pattern dates from the 1700s, when English freely combined an adverb with a verb's -ing form to describe how someone behaves (compare "easy-going", "slow-moving"). The hyphenated spelling remains standard in British English; American writers often close it up as "hardworking".