Dare is used in two ways – as an ordinary verb and as an auxiliary verb.

As an ordinary verb

As an ordinary verb, dare is followed by the infinitive with to. Questions and negatives are made with do.

Do you dare to say what you think?
she dares to say what she thinks.
She didn’t dare to open the door.

Ordinary dare has the -s marking in the third person singular.

I dare to say what I think.
She dares to say what she thinks.
They dare to say what they think.

As a modal auxiliary verb

As an auxiliary verb, dare is followed by an infinitive without to. Questions and negatives are made without do.

She daren’t say what she thinks.
She dare say what she thinks.
Dare she tell him?

Dare is not a common verb in modern English. People generally use other expressions to express the same meaning.

I am not afraid to say what I think.

Ordinary dare is more common than auxiliary dare. It is mostly used in
questions and negatives.

I don’t dare to go out at night.
I heard the knock, but I didn’t dare to open the door.

You dare!
The expressions You dare! and Don’t you dare! are sometimes used to
discourage people from doing unwanted things.

‘Mummy, can I wear that short skirt to school?’ ‘You dare!’