Sometimes we download movies without subtitles , In Mac you can easily add subtitles for the movie with Subtitle app. It fetches the subtitles for movies and TV shows easily. The app looks like clapperboard, and
Once you open the app, just drag a video onto the app interface, it downloads the subtitles from OpenSubtitles database. It is very simple to use to grab subtitles for a movie without putting much effort to find them.