A casual expression used to indicate consent, permission, reassurance, or that something is okay (e.g., 'that's fine', 'no problem', 'sure'). Used in informal contexts.
「明日手伝ってもらえる？」「いいよ、何時に行けばいい？」
"Can you help me tomorrow?" "Sure—what time should I come?"
「コーヒーいる？」「いらない、いいよ。」
"Do you want some coffee?" "No thanks, I'm fine."
友達にお礼を言われて「いいよ」と軽く返すことが多い。
When a friend thanks me, I often reply casually with "it's okay".
「この書類、コピーしておこうか」「いいよ、自分でやる。」
"Shall I make copies of this document?" "No, it's okay—I’ll do it myself."