Writing for video is different than writing for print.
The words support the pictures. And that means less is more, especially when it comes to narration.
Prose written for films should be like poetry, best when read aloud. The grammatical rules, whilst important, are secondary to rhythm and simplicity.
An example of my writing for video:
Video for the national headquarters of the Episcopal Church (Emmy nominated)
Fundraising video for the Episcopal Diocese of Southwestern Virginia.
Hands-on work helping others.
Continuing Medical Education training video.