Meaning of hard in English
1. firm, rigid, or solid, not easily broken, pressed down, or pierced
a hard ground[wood, stone, bread, bed, ...]
Turtle shells are very hard.
Diamond is the hardest of all gems.
His abdominal muscle is (as) hard as rock.
2. severe
a hard time[life, lot, fate, childhood, illness, ...]
a hard problem[question, choice, ...]
a hard lesson[book, language, ...]
a hard job[work, task, ...]
The question is hard to answer.
His explanations are hard to understand.
He is hard to please.
The news is hard to believe.
4. diligent and hard-working
a hard worker
He is hard at work.
5. unpleasantly cold, wet, or dark
have a hard weather[winter, rain, ...]
a hard heart[nature, ...]
a hard teacher[master, father, ...]
a hard treatment[dealing, bargain, training...]
a hard law[sentence]
Bob is hard on his son.
1. earnestly
work[study, think, run, ... ] hard
2. heavily
It is raining very hard.
3. severely
I am hard pressed for money.
4. forcefully
Please knock on this door hard.