self-confident

Self-confident means sure of your own abilities. You expect to be able to do the thing, and it shows.

The word is a compliment, though a slightly guarded one, because English is nervous about too much of it: self-confident is good, overconfident is not, and arrogant is where it ends up if it goes too far. It differs from confident on its own by pointing inward — you can be confident about the weather forecast, but self-confident is always about yourself. The noun is self-confidence, and its absence, a lack of self-confidence, is one of the commonest things people say about themselves.