吸ってた

was smoking, was inhaling

→ 吸う
吸っ inhale, breathe in + Te-form (conjunctive) + Past tense
verb · imperfect indicative Rare #38,805
was smoking Casual contraction of 吸っていた.
JA: 公園でたばこを吸ってた。
EN: I was smoking a cigarette in the park.
was inhaling Casual contraction of 吸っていた.
JA: 彼は深く息を吸ってた。
EN: He was inhaling deeply.
Conjugation of 吸う
Indicative imperfect
吸ってた

昔はタバコ吸ってたんだよね

You used to smoke, right?

若い頃はタバコを吸ってた

I used to smoke when I was young.

トムタバコ吸ってた知らなかったんだ

I didn't know Tom smoked.

今はタバコ吸わないけど昔は吸ってたんだよ

I don't smoke now, but I used to.