Tim Bowen stays in our good books with a shelf full of literary idioms.

If you are in someone’s bad books, they are annoyed with you for some reason. It might be a good idea to try and get back in their good books so that they are pleased with your efforts or behaviour again.

If you can read someone like a book, you are able to understand very easily what they are thinking or feeling, usually because you know them very well. A closed book is someone or something that you do not know or understand anything about, as in 'Indian classical music is still a closed book to most people'. It can also be used to refer to something that you accept has completely ended, as in ‘As far as she is concerned, her marriage to Edwin is a closed book’. An open book, on the other hand is something or someone that is easy to find out about or understand, because nothing is kept secret, as in 'Her life was an open book'.

To do things by the book is to do them correctly, following all the rules or systems for doing something in a strict way, as in ‘He always tried to do everything by the book’. If you are brought to book, you are punished or forced to explain your behaviour publicly after doing something wrong, as in ‘If policemen have lied, then they must be brought to book’. In that situation, it is quite likely that the relevant authorities will throw the book at them (punish them very severely). In my book (in my opinion), however, you should never judge a book by its cover (form an opinion about someone only from their appearance).