Hello native English speakers. Question about the following four sentences. 1. It cannot be but that the man is honest. 2. It cannot be that the man is honest. 3. It can be but that the man is honest. 4. It can be that the man is honest. Question: Which is grammatically correct? What does the “It” respectively refer to ? What does the conjunction “but that” function as by grammar here? Rewrite the sentences above in an easy way for me to understand (due to my terrible and poor English)