To find out means to discover the true, often negative, nature of something, or to detect a wrongdoing. It is usually (but not always) associated an offense.
- As soon as she found out (= to detect a wrongdoing) that her husband had been cheating on her, she hired a divorce attorney.
- The concerns, fed largely by unease over military operations in southern Afghanistan that are progressing slower than anticipated, spurred lawmakers to schedule last-minute hearings this week to assess progress on the battlefield and within the Afghan government. "The hearing is an attempt to find out (= to discover the truth) what is going on in Kandahar," said a Senate Armed Services Committee aide, adding that Sen. Carl M. Levin (D-Mich.), the panel's chairman, "is particularly focused on whether there has been a change in strategy or timetable for the Kandahar campaign." (Washington Post, June 15, 2010)
- Scientists at the Carnegie Institution of Washington at Stanford University synthesized carbon emissions and trade patterns and found (= discover through study) that more than one-third of CO2 emissions related to the consumption of goods and services in developed countries are actually emitted outside their national borders. (Time, March 9, 2010)
- I finally found (= discover through search) my sister's journal in her dresser. I am so tempted to read it, but she will get very upset if she finds it out (= detect a wrongdoing; "it" refers to the fact that I read her journal).
