re: On Reddit, how do I go back and see if someone replied to my comment in a thread?

If you're on a computer, look at the upper right side and click on your user name. When the drop down menu pops up click profile. From there you can use "overview", "comments", and "posts" to look at how people have responded to your posts. There's also a little bell graphic that's always at the top on the middle right hand side that notifies you when a person has directly responded to you or once you get 10 or so up votes.