1. Use can, could and would when you want to make a polite request or politely ask someone for something. Could and would have the same meaning
Could and would are modals. Modals are verbs that are usually used with other verbs to express certain ideas. The verb that follows could and would is in the simple form.
2. When your request contains another question, use statement word order in the second question.
3. Please is often used to make the question even more polite.
4. To answer politely, use these typical responses. When we say no, it's polite to give a reason.