5 Tips for Writing Effective Scripts For Clients:
The narration is the voice of your client. The personality in that voice is the key to how well it resonates with a specific audience. Unless you’re video is to be played at a conference of English teachers, perfect grammar is not always required.
— via Masters of Motion, which I think used to be Canon Filmmakers.
Solid, practical advice. If you don’t find scriptwriting challenging you’re doing it wrong.