I have some questions concerning the use of punctation in English grammar. 1. If you are to say e.g.: 'She received a letter, too.' Must/should you have the comma there? 2. If you are to use the word 'but' should you use the comma as you would with the word 'and'? By this I mean that when you use 'and' between two clauses you need to have a comma before 'and,' but if you have an clause and one phrase, you don't use a comma. Is what I've said here correct? 3. I wonder at the use of apostrophe in genetive. I've tried to figure it out, but I can't seem to on my own. E.g. the examples in my Oxford Advanced dictionary say: My friend's brother the waitress's apron King James's crown/James' crown The students' books the women's coats Now, I've learnt that if there's an 's' at the end of a word you only put an apostrophe and no 's' at the end. However, here 'waitress's' has an extra 's' while 'students'' don't. Further, the it says that you can say either 'James's' or 'James'.' From this I understand that either: a) How you do it optional as long as you are consistent. b) 1. If the word is singular, you must have an 's' after the apostrophe. 2. If it is a name, you can choose whether or not to have an 's' after the apostorphe. 3. If a word is plural, you are not to have an 's' after the apostrophe.