A section in A Comprehensive Grammar of the English Language (Quirk et al., 1985) is dedicated just to that question of distinguishing modal "dare" from lexical "dare".
(CoGEL § 3.42) dare and need
Dare […] can be constructed either as main verbs (with to-infinitive and with inflected -s, -ing and past forms), or, under restricted conditions, as modal auxiliaries (with the bare infinitive and without the inflected forms).
|
MODAL AUXILIARY |
MAIN VERB |
Positive |
— |
He dared to escape. |
Negative |
He daren't escape. |
He doesn't dare to escape. |
Interrogative |
Dare we escape? |
Do we dare to escape? |
Negative-interrogative |
Dare he not escape? |
Doesn't he dare to escape? |
The modal construction is restricted to nonassertive contexts […], ie mainly negative and interrogative sentences, whereas the main verb
constructionn can almost always be used, and is in fact more common. The
auxiliary construction with dare […] is rarer in AmE than in BrE, where
it is also quite rare.
As a modal, dare exhibits abnormal time reference […] in that it can
be used, without inflection, for past as well as present time:
- The king was so hot-tempered that no one dare tell him the bad news.
The main verb form dared (to) might also occur here.
Note
[…]
[b] Blends between the auxiliary construction and the main verb construction occur and seem to be widely acceptable […]:
- They do not dare ask for more.
- Do they dare ask for more?
These two examples combine the do-support of the main verb construction with the bare infinitive of the auxiliary construction. On the hypothesis that there are two different verbs (the main verb DARE and the auxiliary verb dare), one would expect these to be ungrammatical; but they are not. The past tense form dared without do-support may be regarded as another example of a blend, since the -ed past inflection is not characteristic of modal verbs:
- They dared not carry out their threat.