아/어 보다
Add -아/어 보다 to a verb stem to mean "try doing" something. It is useful for new actions, testing something, or making an attempt. In the story, 입어 보려고 했는데 means "I was going to try on" the jacket. Example: 재킷을 입어 봤어요. = "I tried on the jacket."
재킷을 입어 봤어요.
I tried on the jacket.
