New subtitles from youtube transcription

[pkbluenite]

How do I set up a preliminary clean txt file as a transcription for basic subtitles by sentences? More specifically: part of the sentence or only one word is at the end of the previous subtitle or line, and I need to solve this without manually moving it to a separate subtitle. Would it be possible to use the first capital letter of the sentence and a period before it? I'm trying to do this in the settings, but I can't get it to work. I hope that makes sense. Thank you for any advice.
Peter