两词都有难之意;但hard侧重于艰苦的指精神上和身体上的感受如：He works hard in order to pass the exam.而difficult多指智力和行动方面的困难,需要智力和技巧来处理完成如：it is difficult for me to work out this maths problem.
在我的生活与学习中,由于自己没有吃苦的精神,说得难听些,有些好逸恶劳,所以虽然并不笨,但是有很多事情对我来说都是hard,而并非difficult,I never work hard,so I can not do anyting.
therefore ,I must learn how to work hard as soon as possible
difficult与hard用作形容词时,均可表示“困难的”之意,一般情况下能互换,但两者之间也有区别：
1.difficult习惯用来修饰需要运用智慧和技巧才能解决的问题,其程度要比hard深.
eg.
The question is too difficult for me to answer.
这个问题对我来说太难了,我答不出来.
We don't think it's difficult to learn a foreign language well .
我们认为学好一门外语并不难.
2.hard习惯用来指体力和精神方面所感受到的困难与艰苦,程度没有difficult深,但语气比difficult强,多用于口语.
eg.
These apples are hard to reach.这些苹果难够着.
It's hard to keep this secret.很难保守这个秘密.
3.hard用作形容词时,还有“坚硬的”“严厉的”“冷酷无情的”之意,而difficult则没有.
eg.
I like hard chairs.我喜欢坐硬座椅.
Don”t be too hard on her.别对她太严厉了.
4.hard还能用作副词,意为“努力地”,而difficult 则无此意.
eg.
Think hard and work hard.认真思考,努力工作.
。