開いてた

was open

→ 開く
開い open + Te-form (conjunctive) + past tense
verb · past indicative Rare #40,629
was open Casual contraction of 開いていた.
JA: 店はもう開いてた。
EN: The store was already open.
Conjugation of 開く

ドアは開いてた

Was the door open?

突然現れた開いてた

The gate that suddenly appeared was open.

— 28年後... 白骨の神殿 (2026)

救急車が到着したとき開いてた

Was it open when the ambulance arrived?

— 落下の解剖学 (2023)

ドアが開いてたこの子は

The door was open. What about this kid?

— どん底作家の人生に幸あれ! (2019)