Hi Nam. I wish you well on your project. Because this is a title I would capitalize the major words and make slight changes: "The Difficulty of Studying English for Vietnamese Students and How to Improve" Also your question: May you help me to correct grammar become better? Because you are asking another person, we say: Will you help me..... The complete question: Will you help me to correct my grammar and become better? If you ask about yourself, we say: May I..... For example: May I borrow your pencil?