着いてる

have arrived, be there

→ 着く
着い arrive, reach + てる Progressive/continuative
verb · indicative Rare #33,793
have arrived, be there Colloquial contraction of 着いている, often describing someone or something that has already arrived or is already at a place.
JA: もう駅に着いてるよ。
EN: I'm already at the station.
Conjugation of 着く
Indicative
着いてる

手紙は着いてるのか

Did the letter arrive?

— セントラル・ステーション (1998)

ズボン床に着いてる

Your pants are dragging on the floor.

彼はもう着いてるはずだ

He should have arrived by now.

列車はとっくに着いてる

The train got here ages ago.

もうほとんど着いてる

I'm almost there.

— ライフ・イズ・ビューティフル (1997)