I have a friend that translates everything from English for his grandmother, so she can watch movies that she does not understand, but he does it by hand in a video editing program. Would love to help him out.
.srt is the lowest common denominator for subtitle files, every subtitling program can import and export those. It's a pretty dumb format though, my biggest issue with it is that it doesn't have support for fixed-position left-aligned subtitles, and it doesn't have support for specifying the font. I understand why, it's to make playback much simpler and resolution-independent, which is why every single video player program or hardware device in existence has support for it.
But if you left-align it with a fixed margin, choose a good font, and use white text on black background, your subtitles are going to be so much easier to read.
(Here's a sample of what I prefer: https://skamenglishsubs.tumblr.com/post/188037245260/subtext...)
(I belong to the tiny minority of people who often mix up the words for left and right, it's both annoying and hilarious.)