おい

おい is a casual, masculine interjection used to get someone's attention. It ranges from friendly to confrontational depending on tone and context.

Functions

1. Getting attention: おい、聞(き)いてるか？ (Hey, are you listening?)
2. Calling out: おい、待(ま)て！ (Hey, wait!)
3. Surprise/disbelief: おいおい (hey hey, come on — used when something unexpected happens)

Register

• Informal and masculine. Primarily used by men speaking to equals or those of lower status.
• Can sound aggressive or rude if used with strangers or superiors.
• Women generally use ねえ or ちょっと instead.
• Not used in formal or polite situations.

Similar interjections

• ねえ: hey (gender-neutral, softer)
• ちょっと: hey, excuse me (politer)
• よう: hey, yo (casual, masculine)