1) I intended to have spent my summer vacation in the country
2) I knew him to be waiting for me that evening -
I would rather say "I knew he was waiting for me that evening)
3) We are to meet at the station at six oclock
4) He is known to have been doing a lot to improve his knowledge of English
5) To read is useful - I would rather say "reading is beautiful"
6) I saw him enter the room - I would rather say "I saw him entering the room"
7) I felt him to be an honest man
8) Have you ever heard him complain of difficulty?
So, I have taken these sentences from a grammar book. However, some of them sound weird to me. My question is are these sentences too formal? How come I have never come across this kind of grammar usage.