Here's a start. Go to the NCH Software web site and get "VideoPad Video Editor".
From my past experience with NCH, be AWARE when you are installing, un-check any additional software it may offer. After install check your start menu for any additional shortcut other than, "VideoPad Video Editor". For example, "NCH Software" and/or "Video Related Programs". Both those are only shortcuts to download more NCH software and safe to delete.
NCH makes some nice free stuff however they are a commercial software company only trying to make a buck. You can't blame them for that, you just have to know what to expect when you download their free programs.
I'm guessing the video clips are already on your computer. Now that you have "VideoPad Video Editor" installed, open your video. At the bottom of the editor you should have any audio tracks. If there really are two audio tracks, (one for each language) you can either remove or mute the one you don't want. You'll then have to re-compile your movie and your done.
If you only have one audio track at the bottom I'm afraid you choices are limited. It would be very difficult to separate the languages from one audio feed. The only choice would be to add an English subtitles track (if it's a movie) with "VideoPad Video Editor" or rename the subtitles track the same as your video and place it in the same directory as your video.
If your video clip is from a movie you can still use a subtitles track (srt file). VideoPad has a very good Subtitles editor which you can use to customize your srt file.
Good luck!