Semi-modal auxiliary verbs, often simply called semi-modal verbs, are verbs that sometimes behave like modal auxiliary verbs. They are also sometimes known as marginal modal verbs.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.
Examples :
1. I dare not press the issue any further.
2. How dare he talk to me like that?
3. No one need know about this.
4. He needn’t have called; I told him I would be late.
5. I used to get up early when I lived in New Delhi.
6. She used to live in Agra.