Be just about to
This expression is used to express the fact that not only had the speaker been intending to do the very thing the other person is suggesting, but that he or she was either just about to do it at that very moment or intended to do so very soon. It can only be used with verbs.
1. While both -(으)려던 참이다 and -(으)려던 참이었다 are acceptable forms of this expression, -(으)려던 참이다 is used to indicate that the speaker was just about to do the action at that very minute, while -(으)려던 참이었다 is used to indicate that the speaker had already been intending to do the action.
Here, ① means that the speaker was just about to buy the book at that very moment while ② means that the speaker had been planning to buy the book from before the time of the conversation.
2. This expression can be used along with phrases such as 마침, 그렇지 않아도, and 안 그래도 when responding to someone who has suggested doing something that the speaker had already intended to do.
3. This expression cannot be used with the future tense.
4. When used at the end of a clause that is followed by another clause in the same sentence, the form -(으)려던 참에 can also be used.
The forms -(으)려고 하다 and -(으)려던 참이다 have the following differences.
The speaker is just about to do something very soon.