长久以来，我都严格执行当初学语法时老师反复强调的圣旨：dare既可以作实意动词，也可以作情态动词。

实意动词（也就是普通动词，第三人称单数需要加s，敢于做某事的“做”前需要加动词不定式to）：

She dares to challenge authority figures.

We don't dare to upset Damon right now.

情态动词（也就是特殊动词，第三人称单数不需加s，敢于做某事的“做”前不需加动词不定式to，通常只用于否定句或疑问句）:  

He dare not go out after dark. 

Dare you try it yourself?

应该说，这样比较简单粗暴的两大类划分方法还是非常管用的，我纵横语法江湖二十多年基本没出过问题。

可是最近接二连三看到这样的句子：

I thought about what I might take out of my pack, but each item struck me as either so obviously needed or so in-case-of-emergency necessary that I didn't dare remove it.

"You getting a cone?" asked Greg, pulling out a couple of dollars. 

"Nah. Maybe later," I said, keeping my voice light to hide my desperation. I wanted a cone, of course. It was that I didn't dare purchase one, for fear of not being able to afford a room. 

I was shivering by now, standing in the snow in my shorts and sweat-drenched T-shirt, but I didn't dare continue on until I got my bearings.

第一次看到没多想，以为是书里偶尔出现的错误。因为按照上面提到的简单粗暴划分方法，要么是I didn't dare to remove it（实意动词），要么是I dare/dared not remove it（情态动词）。怎么也不会是I didn't dare remove it。（didn't意味着实意动词用法，remove前面没有to意味着情态动词用法，到底想怎样啊？）

可是，当我在同一本书里第四次看到这样的用法时，我知道不是typo这么简单的事了。赶紧四处搜刮了一下，终于找到答案。

简单粗暴的分类大致是对的，但还有一种漏网之鱼的情形：dare作实意动词时，动词不定式to do something的to可省略。换句话说，敢于做某事的“做”前并不是必须加to。

所以，上面提到的实意动词的例子，也可以这么说：

She dares challenge authority figures. (= She dares to challenge authority figures.)

We don't dare upset Damon right now. (= We don't dare to upset Damon right now.)

I didn't dare remove it也属于这种用法。

这种漏网之鱼的情形确实很让人头疼，因为它使得很多看似矛盾的用法同时成立。

Tim dares to go there. 正确

Tim dares go there. 正确

Tim dare go there. 正确

Does Tim dare to go there? 正确

Does Tim dare go there? 正确

Dare Tim go there? 正确

把过去的时态掺和进去，也是如此：

Tim didn't dare to go there. 正确

Tim didn't dare go there. 正确

Tim dared not go there. 正确

Did Tim dare to go there? 正确

Did Tim dare go there? 正确

Dared Tim go there? 正确

此外，dare作情态动词虽然可以有过去式，但用或不用都正确，看个人偏好。所以Tim dared not go there也可以说Tim dare not go there，Dared Tim go there?也可以说Dare Tim go there? 总体看来，不用过去式是更流行的选择。

有没有头晕？

说实话，dare这个词真是太作了（need也是既可以作实意动词，也可以作情态动词，但它远不及dare作）。我不是语言学家，也由衷觉得没有必要把所有的概念都搞得那么清楚，只要确保自己在使用时不会冒出错误的句子就行了。所以，从实用主义的角度出发，只需要记住：dare这个词因为用法太多，基本上怎么用都对！加不加s，加不加to，加不加过去式，都能找到理论依据。只有一种情形是肯定错的：dare作情态动词，但又跟着to。（带有质问口吻的How dare someone do something属于情态动词用法，所以一定不加to。）

直观一点：

Do you dare to do this? 正确 （回答：Yes, I do. / No, I don't.）

Do you dare do this? 正确 （回答：同上）

Did you dare to this? 正确 （回答：Yes, I did. / No, I didn't.）

Did you dare do this? 正确 （回答：同上）

Dare you do this? 正确 （回答：Yes, I dare. / No, I dare not.）

Dared you do this? 正确 （回答：Yes, I dared. / No, I dared not.）

How dare you do this? 正确 （无需回答，问话的人只是想发泄情绪）

Dare you to do this? 错误

Dared you to do this? 错误

How dare you to do this? 错误