〜までに

## What it means までに marks a **deadline** — it means "by [a certain time]", pointing to the latest moment something should happen.

## When to use it Attach までに right after a time word or a clause describing an event. 金曜日までに means "by Friday", and 授業が始まるまでに means "by the time class starts". The action described usually happens once, at some point no later than that deadline.

## Don't confuse it with Plain まで (without に) means "until", describing a **continuous range** of time — 五時まで働きます means "I work until five o'clock", i.e. working the whole stretch of time up to five. までに instead means "by five o'clock" — a single point where something must be done or completed, not a stretch of ongoing action. This is the single most common mix-up for beginners with this pattern.