If you have subtitle file then its very easy to embed the file with the video permanently.
Also see here- How to make a subtitle file.
You can add the subtitle file in your video via online or using software. This is recommended to do this task in online. By doing this you can save your time. This task is very easy. I prefer to use this online link for adding subtitle permanently in your video. Follow these simple steps-
-Go through the link. Choose the file and upload the video.
-Upload the subtitle file.
– Change the font size depending on your demand and click on “add subtitle” button. Now, wait for a while for an output video.
– Save the output video when it done.
Also See-
Extract subtitle from YouTube video
How to make a subtitle file using notepad
How to translate, create and add any new language subtitle in video easily