いきなり

いきなり is an adverb meaning "suddenly," "abruptly," or "without warning." It describes an action or event that happens unexpectedly, with no prior notice or buildup. It emphasizes the lack of preparation or gradual transition – something just happens out of nowhere.

いきなり vs. 突然（とつぜん）

Both いきなり and とつぜん突然 translate to "suddenly," but there is a nuance difference. とつぜん突然 focuses on the unexpectedness of an event from the observer's perspective – something happened that was not anticipated. いきなり, on the other hand, emphasizes the abruptness and lack of proper steps or warning – someone skipped what would normally come first, or an action happened with no lead-up at all.

In this example, とつぜん突然 would sound less natural because the emphasis is on skipping the expected preamble, not just on the surprise factor.

Here, とつぜん突然 is more natural because earthquakes are inherently unexpected events. いきなり could also be used but would add a more personal, colloquial feel.

Usage notes

• いきなり is used in both spoken and written Japanese but has a slightly more colloquial feel than とつぜん突然.
• It can modify verbs directly by placing it before the verb.
• It often appears in narratives to create a sense of surprise or drama.
  いきなりむずかしい難しいもんだい問題をださないで出さないでください。

  Please don't throw difficult questions at me out of the blue.