The little boy daren't go out at night.（daren't 是情态动词,其后接动词原形go;
The little boy doesn't dare to go out at night.（doesn't是情态动词,其后接动词原形dare,dare to do sth 敢于做某事
类似还有need,试作比较.
the old man doesn't need to get off the bus (need是实义动词)
the old man needn't get off the bus（need是情态动词）
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