read like a book

read (one) like a book

To easily analyze and thoroughly understand one, especially one's emotions, motivations, etc. You won't be a very successful thief with that nervous demeanor—the cops will read you like a book. I can read you like a book, and I can tell that something's wrong, so please tell me what it is.
See also: book, like, read
Farlex Dictionary of Idioms.

read someone like a book

Fig. to understand someone very well. I've got John figured out. I can read him like a book. Of course I understand you. I read you like a book.
See also: book, like, read
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • read (one) like a book
  • read somebody like a book
  • read someone like a book
  • know (someone or something) like a book
  • know like a book
  • search your heart/soul/conscience
  • search (one's) heart
  • search (one's) soul
  • speak (one's) language
  • speak someone’s language