いたの

was there; were there

→ 居る
phrase Uncommon #9,410
was there; were there A casual form combining the past tense of いる (to be/exist, for people and animals) with の. In questions, の adds a conversational, explanatory tone.
JA: さっき、誰かいたの?
EN: Was someone there earlier?

パパは私たちのアパートの下の事務所にいたのよ。

Dad was in the office downstairs from our apartment.

お魚の上にいたの!

It was on top of the fish!

— 崖の上のポニョ (2008)

なんで屋根の上にいたの?

Why were you on the roof?

私はあそこにいたの

I was there.

— アイム・スティル・ヒア (2024)

そこにどのぐらいいたの?

How long were you there?

トムはそのパーティーにいたの?

Was Tom at the party?

流しの下に女の子がいたの

There was a girl under the sink.

— 箪笥<たんす> (2003)

父さんまだいたの?

Dad, you're still here?

— いまを生きる (1989)

部屋には他に誰かがいたの?

Was there anyone else in the room?

トムのパーティーにいたの?

Were you at Tom's party?

閉店までいたの

Did you stay until closing time?

— アイム・スティル・ヒア (2024)

車の中に誰かいたの?

Was there someone in the car?

あ西宮さんいたの?

Oh, Nishimiya, you were here?

— 映画 聲の形 (2016)

どのくらいいたの?

How long were you there?

部屋には誰かいたの?

Was anyone in the room?

あらまだいたの

Oh, you're still here?

— ウィキッド ふたりの魔女 (2024)

そうやって一晩中サイロの中にいたの

So you were inside the silo all night?

— When Marnie Was There (2014)

そのパーティーにいたの?

Were you at that party?

ボストンにはどれくらいいたの?

How long were you in Boston?

若い頃私を見てすぐ逃げ出す男性がいたの

When I was young, there was a man who would run away as soon as he saw me.

— レベッカ (1940)

まだいたの?

You're still here?

— マルホランド・ドライブ (2001)

いたの?

Were you there?

— マルホランド・ドライブ (2001)

そこに誰かいたの?

Was someone there?

彼女って、そこにどのぐらいいたの?

How long was she there?