Use when an event or outcome was not anticipated or seen as a possibility.

Unexpected Events

Often used to express irony or surprise at a situation that was unlikely or not predicted.

Irony and Surprise

Can express regret when looking back at a situation that one feels should have been predictable.

May be used literally when someone visually identifies another person approaching.

Implies the observer is attentive and noticing others arriving or approaching from a distance.

Used when someone is expecting another's arrival and is on the lookout for them.