急!not only...but also 与 both.and.都有不仅.而且.,在使用上有没了区别,或者都可以用,只是着重点不同?比如 This book is_______ useful________interesting.有人说 both...and 只用来连接名词代词,但字典上解释both and 可以连接名词,代词,形容词,动词等,如：字典上的例句有：He both fears and hates at once(他亦惧亦恨.） 那么应该也可以说He not only fears but also hates at once.个人认为,是不是both and 并列的两点在着重程度上是相同的,而not only ..but also.. 着重点在后者上?是这样吗?求权威回答,谢谢!

"This book is not only useful but also interesting" is good, but I will use it as " This book is not only interesting but also useful". it is interesting, and plus useful.
if you say: "This book is both useful and interesting", this is not English any more, 'cause no one will use it that way.
not only ... but also is add on.
both ... and is parallel.

我觉的你想的是对的.我不是权威,今年高考136分,只是发表一下意见

前者和后者在语气上是不一样的,你在强调两者一样时用both and,而你在强调不知有并且还有时就用not only ..but also.其实这不难理解就是在中文中强调不同就会使用不同的词组.