datsuijo o deta totan ni, tomodachi ga onsenmanjuu o motte kita.

direct object particle

Breakdown of datsuijo o deta totan ni, tomodachi ga onsenmanjuu o motte kita.

• 友とも達だち: friend
• が: subject particle
• 出でる: to leave

Questions & Answers about datsuijo o deta totan ni, tomodachi ga onsenmanjuu o motte kita.

Why is を used in 脱衣所を出た? I thought 出る is intransitive.

Good question. 出る is intransitive, but Japanese still often uses を with certain intransitive movement verbs to mark the place someone leaves, passes through, or moves along.

So in 脱衣所を出た, 脱衣所を means out of the changing room / leaving the changing room.

This use of を is common with verbs like:

• 家を出る = leave the house
• バスを降りる = get off the bus
• 道を歩く = walk along the road
• 橋を渡る = cross the bridge

So this を is not marking a direct object in the usual English sense. It is marking the place associated with movement.

Why is it 出たとたんに and not 出るとたんに?

Because とたん（に） usually attaches to the plain past form of a verb.

Pattern:

• V-た + とたん（に）

So:

• 出たとたんに = the moment someone went out / as soon as someone left

This is a fixed grammar pattern. Even though it refers to two events happening almost back-to-back, the first verb is normally in the past form.

More examples:

• 座ったとたんに、電話が鳴った。
  The moment I sat down, the phone rang.

• 窓を開けたとたんに、虫が入ってきた。
  The moment I opened the window, a bug flew in.

What does とたんに mean exactly?