worth, worthy, worthwhile用法区别一：
worth表示“值，值得”，可用表语或后置定语，其后一定要有名词或动名词作宾语，但不能接不定式。如：
The book is worth $ 100.这本书值100元。
The book is worth reading.这本书值得看。
This is a book worth reading.这是一本值得读的书。
worth, worthy, worthwhile用法区别二：
worthy表示“应得，配得上，值得”，常作表语或后置定语，后接不定式，或of加名词或动名词。如：
His behaviour is worthy of great praise. 他的行为应受到高度赞扬。
I think he is not worthy of her. 我认为他配不上她。
The book is worthy of being read. = The book is worthy to be read.这体书值得读。
This is a book worthy of being read. = This is a book worthy to be read.这是一本值得读的书。
worth, worthy, worthwhile用法区别三：
worthwhile表示“值得的，值得干的，值得花时间/金钱/精力的”，可作定语、表语或宾补。如：
Nursing is a very worthwhile career. 护理是很值得干的职业。(定语)
The visit to Paris is worthwhile. 去巴黎访问是值得的。(表语)
I think it worthwhile to read the book. 我认为看那本书是值得的。(宾补)
还可用于It is worthwhile doing /to do sth. 句型。如：
It is worthwhile reading /to read the book.= Reading /To read is worthwhile.这本书值得看。
有时可在worth与while之间插入one's。如：
The work is worth your while. 这工作值得你去做。
It is worth our while to discuss the question. 这个问题值得我们讨论。
Make it worth sb.'s while 酬谢某人。如：
They promised to make it worth her while if she would take part. 他们许诺说她要是参加，就给她报酬。
