JacquiD makes a very important point. dare + v sounds strange in affirmative sentences (We don't usually say: I dared tell him. / Did you dare tell him?) Instead, use dare + to + v for affirmative. (I dared to tell him. / Did you dare to tell him?) Dare + v is really only used for negative sentences. (I didn't dare tell him.) Other common uses: * Don't you dare + verb! (= a very strong warning. Don't you dare speak to me like that!) * Do I dare? A: You should ask the boss for a raise. B: Really? Do I dare? ( = Do you really think it's a good idea?)

Dare is both a normal verb and a modal verb. As a normal verb it is used with 'to' infinitive. 'I dared to tell him what I thought.' 'I didn't dare to tell him what I thought.' As a modal verb it is used without 'to' 'I dare look at him.' 'I didn't dare look at him'. The meaning is the same just the structure is different. But these days the modal verb form is not used so much in the positive or questions.

They're both right. There's no difference.