I take my script into a room to start recording, and I start bumbling around phrases and spend a lot more time re-writing phrases to sound more conversational or to simply avoid tongue-tying phrases. It is surprising how difficult it is to write for how people speak. Sometimes you don’t know a phrase is bad until you say it out loud.
If you write scripts for other people to read and record, the best way to avoid this is to read your scripts out loud, as if you are recording it. Do that and you will find yourself catching all sorts of mistakes.