The document defines suggestion and outlines ways to ask for, give, accept, and refuse suggestions in English. It provides formulas and example phrases for each case. Asking for a suggestion involves using modals like "What do you advise me to do?". Giving a suggestion can use "should" or "ought to" for regular situations and "had better" for dangerous ones. Accepting a suggestion may use agreeing words like "yes" or "good idea". Refusing politely involves phrases like "Thanks, but that won't work because..." or "That's a good idea, but...".