Knowledge is power. Knowledge of vocabulary is power squared. When you have a good vocabulary, you can kiss up to some people and put down others. You like the word munificent, meaning generous or attractive? Use it to score some parent points. Tell your mother at allowance time that she is the most munificent mother on the block and don't be surprised if she shares a bit more of her paycheck with you that week. Mention to your father that you've always considered him a paradigmatic (example or model) parent and listen to him brag to his buddies about what a good relationship he has with his son. All teachers like to be told that their lucid (clear) and unambiguous (clear, understandable) explanations really help you.