うちに vs あいだに

While you still can vs during that period

'Eat it while it's still hot.' 'While I'm still in Japan...' 'While he was sleeping, I cleaned up.' — うちに and あいだに look similar but feel very different.

What you'll learn

• うちに = while (state still holds) / before it changes — emphasizes seizing a fleeting opportunity
• ないうちに = before ~ happens (暗くならないうちに)
• あいだに = at some point within a period — no urgency, just 'during that time'

JLPT N3 Japanese self-study — interactive practice, instant feedback, completely free.