まさか

まさか is an interjection used to express strong surprise or disbelief about a situation that is unlikely or unexpected. It often appears when reacting to news or a turn of events that one finds hard to believe. It can function as a standalone exclamation or be attached to a clause with とは(think/know) to emphasize realization or astonishment about a fact. In everyday conversation, it carries a nuance of “No way,” “You’ve got to be kidding,” or “I never would have imagined.” Use it when reacting to surprising information, especially when the probability of the event is considered very low.