I have this sentence that forms a disaster for me. I know what is wrong with it but I can't find some suitable fixes.
The sentence is:
I'm actually wondering why did the chef keep silent all that time, with knowing the slightest details about me and her boyfriend?
1- I feel like it would be more proper for keep silent to be kept silent, but it is in a question form, so it won't fit.
2- With knowing, I find it improper English. So, I tried to replace it with "With her knowing","despite her knowing", and "although knowing". But I find them having the same problem in common.