What it means
いきなり is an adverb meaning that an event or action happens suddenly and without warning or preparation. It often conveys the speaker’s surprise and can modify a verb or an entire clause. It is common in both familiar and polite sentences because the adverb itself does not change with register.
Usage note
いきなり emphasizes that something begins or occurs without a preceding step, warning, or gradual transition. 急に also means “suddenly,” but it focuses more generally on an abrupt change and is often less focused on the lack of preparation.
How to use it
いきなり電車が止まりました。
The train stopped suddenly.
いきなり電車が止まった。
The train stopped suddenly.
Example sentences
会議の途中で、部長はいきなり新しい企画書を配り始めた。
In the middle of the meeting, the department manager suddenly began handing out a new proposal document.
駅に着くと、友人はいきなり海外旅行の計画を話し始めた。
When I arrived at the station, my friend suddenly started talking about plans for an overseas trip.