Reading a book on grammar and I am not sure about few phrases. The book gives you an example of what not to do but doesn't follow up with a correct version. So here's the wrong version of the phrase I am looking to get help with: Adult Learner's Week The above is weong for where the apostrophe is placed. However, where's the right place? My guess is Adult Learners' Week. Wrong way: Citizens Advice Bureau. Right way: Citizens' Advice Bureau? Wrong way: Mens Toilets. Right way: Mens' Toilets? Wrong way: Ladie's hairdresser. Right way: Ladies' hairdresser?