[A] 形容词
(1) Is English a hard language to learn? 困难的
(2) The ground is too hard to dig. 硬
(3) a hard life; hard times. 艰难的
(4) The water is hard in this part of the country. 硬水
[B] 副词
(1) He works very hard; Think hard.努力地
(2) Don't hit him too hard 重重地
(3) He stared hard at the man. 紧紧地
[C] harden =动词: The earth was hardened...
词典上hard的用法如下：
a.形容词
1. 硬的,坚固的
The ice is as hard as rock.
冰像石头一样硬。
2. 困难的,费力的[+to-v]
George is hard to get along with.
乔治很难相处。
3. 猛力的;辛苦的
He gave the door a hard kick.
他猛力踢门。
4. 刻苦的;努力的[B]
She is a hard worker.
她是一个工作十分勤奋的人。
5. 艰难的;难受的
I know that he has a very hard life.
我知道他日子过得很艰难。
6. 冷酷无情的;严厉的;严格的[(+on)]
She is too hard on her pupils.
她对学生太严格了。
7. (气候)酷寒的
It was a hard winter.
那是一个严寒的冬天。
8. 语发硬音的(如c,g念成[k][g])
9. (水)硬质的
10. (毒品)毒性强的,使成瘾的[B]
11. 确实的;不容怀疑的[B]
We confronted him with hard facts.
我们把铁的事实摆在他的面前。
12. 军设重防的;(导弹发射场或导弹)设于地下可免受敌方空袭的
ad.副词
1. 努力地;艰苦地
She tried hard, but failed.
她努力尝试过,但未能成功。
2. 猛烈地;重重地
It's raining hard.
雨下得很大。
3. 困难地;困苦地
The old man is breathing hard.
这位老人呼吸困难。
4. 牢固地,紧紧地
He held hard on to the rope.
他牢牢抓着绳子。
5. 接近地;立即地
One misfortune followed hard on another.
不幸接踵而来。