Which of the following is the correct?(or are they both correct?)<br/><br/>a) I thank you all for the birthday wishes.<br/><br/>b) I thank all of you for the birthday wishes.<br/><br/>2nd question,<br/><br/>a) I never did anything for you.<br/><br/>b) I never do anything for you.<br/><br/>Please explain to me the differences above.