-다가 function as 보조사
Here's an excerpt from Daum online dictionary:
다6
형태분석 : [다(다가)]
조사
장소를 나타내며 일부 모음으로 끝나는 부사어나 조사 ‘에’, ‘에게’, ‘한테’, ‘으로’ 또는 연결 어미 ‘-어’의 뒤에 붙어, 그 의미를 보다 뚜렷하게 해 주는 보조사.
여기다 버리자.
거기다 놓고 가거라.
제가 망치로다 책상을 내리쳤거든요.
그 녀석을 잡아다 따끔하게 혼을 내 주어야 해요. <-------------------- Ex. 3
What catches my attention is the third example
I thought 다가 used as a 보조사 would only make sense after 에,로 and that kind of postpositional forms. The third example clearly uses it behind a conjugated verb form to distinguish from its other meaning (contrast with 잡다가). This is not a form that I am familiar with. From the definition above, it seems that it lends a bit more emphasis on the action performed rather than a normal connective role. Is this common at all? Could anyone relate a few more examples of this particular usage?