-(으)려다가

wanted/meant/tried to do x, but then...

Explanation

This expression is used to indicate that the subject had intended to do some action but then decided to quit or to do something else instead.

It is the shortened form of -(으)려고 하다가.

It is also used in the form -(으)려다 in which 가 is omitted.

It only attaches to verbs.

Details

1. For this expression, the objects of both the preceding and following clauses must be the same.

(내가) 커피를 주문하려다가 잠이 안 올 것 같아서 내 친구가 주스를 주문했다. ✕
→(내가) 커피를 주문하려다가 잠이 안올 것 같아서 (내가) 주스를 주문했다. ✓

2. This expression is also used when indicating the sudden interruption of, or change in, some gradually changing or newly created situation or state of affairs.

날씨가 선선해지려다가 다시 더워졌다.
The weather had been becoming cool, but then it became hot again.
드라마가 재미있어지려다가 말았다.
The drama (series) was getting interesting and then stopped (getting interesting).

Kimchi Reader

Contraction of -(으)려고 하다가. Express that the speaker intended or tried to do something, but "interrupted" the intention or attempt by doing something else, leaving the original intention unfulfilled.