Example: Disturbing.Behavior.1998.720p.BluRay.x264.mkv and Disturbing.Behavior.1998.720p.BluRay.x264.srt . Place both files in the same folder.
If the dialogue doesn't match the audio (which can happen if the BluRay rip has a different frame rate than the subtitle was made for): subtitle Disturbing.Behavior.1998.720p.BluRay.x...
Use a site like SubtitleTools.com to "Shift" the entire timing if it is consistently off by a few seconds. Example: Disturbing
Use a player like VLC or MPC-HC . In VLC, you can also simply drag and drop the .srt file onto the video window while it's playing. Troubleshooting Sync Issues subtitle Disturbing.Behavior.1998.720p.BluRay.x...