The document discusses using modal verbs like should, shouldn't, need to, and could to give advice or make suggestions. It provides examples of using these verbs to give strong advice about what is right, necessary, or a good idea to do. Suggestions can also be made more softly using phrases like "Why don't you..." or "It's a good idea to...". The document concludes with filling in sentences with the correct modal verb "should" to complete pieces of advice.