Here's why and how to fix it:
* Missing Subject: The sentence is missing a subject after "Let". We need to know who is doing the letting know.
* Awkward Construction: Using "or" to connect "Brittany" and "you" creates an awkward structure.
Here are some correct ways to phrase this:
* "Let Brittany and you know." (This assumes the speaker wants to inform both Brittany and the listener)
* "Let Brittany or me know." (This assumes the speaker is offering the listener a choice of who to inform)
* "Please let Brittany or you know." (This assumes the speaker is asking a third party to inform either Brittany or the listener)
Make sure the sentence clearly indicates who is being informed and who is doing the informing!