a subtitle vs subtitles
Solution 1:
If you are creating a single srt file the sentence would be
I created a subtitle for this film
If you create 2 or more srt files the sentence would be
I have created multiple subtitles for the this film
If you are creating a single srt file the sentence would be
I created a subtitle for this film
If you create 2 or more srt files the sentence would be
I have created multiple subtitles for the this film