The following verbs are often called "semi-modals" because they are partly like modal helping verbs and partly like main verbs:
-- Need / Dare / Used to

The two verbs 'dare' and 'need' have characteristics of both modal verbs and main verbs. Because of this, they are called semi-modals. They sometimes behave like modal verbs and do not add -s to the form that goes with he, she, and it. That is, they have no 3rd person singular inflection. They are then followed by the base form of a main verb.
Example _
1. Need I say more?
2. Dare I ask how the project’s going?

The verb 'used to' is a ‘marginal’ modal verb. Unlike the other modal verbs, it is only found in the past tense.
1. Ram always used to go for a run before breakfast.