Studying all night will be good for neither your grades nor you health.

这个英文句子是很标准的，非常通顺。网友觉得读起来不通顺，是因为你理解英语句子是先在心理翻译成汉语，然后才理解。

这个句子可以改为下句，意思是一样的，只不过后者没有前者的否定语气强烈：

Studying all night will not be good for your grades or you health.

注意表示既不...也不...时，不能用not A and B, 要用not A or B.

例如：汉语“我没有汽车，也没有摩托车。”翻译成英文则是：

I have neither a car nor a motorbike.

I don't have a car or a motorbike.

I have no car or motorbike.

如果用and, 意思就成了：我不是既有汽车又有摩托车（我只有其中之一）。

英语的否定可以是否定谓语，也可以否定谓语之外的其它成分，效果是一样的。

You can't find this anywhere else. 否定谓语

You can find this nowhere else. 否定状语

I don't have any money. 否定谓语

I have no money. 否定宾语

I don't know anything about it.

I know nothing about it.

I won't tell anyone.

I will tell no one.

I won't do it by any means.

By no means will I do it.

I won't do it at any time.

I will do it at no time.

最后一句：I will do it at no time.网友是否也觉得读起来不通顺。可这却是标准的英语。逐字翻译成汉语你觉得不通顺是汉语通常采用动词否定的缘故。