That vs Which: Difference and Comparison - Basic English Grammar

In this video, Alisha answers 5 questions. - When it comes to inversions in formal English to give emphasis. What can you say about it? - Can you explain the difference between which and that? - Let me know whether you can use "if I were you, I will..." - Authorisation/ Authentication difference? - My question is about of structure "To be to". Could you explain how it works?