表扬 (biǎoyáng) is the most common, everyday word for 'praise', often used when a superior praises a subordinate (teacher to student, boss to employee). 夸奖 (kuājiǎng, HSK6) is more informal and personal, like complimenting someone's appearance or effort; 称赞 (chēngzàn, HSK5) is more formal/written, used in public acknowledgments. 恭维 (gōngwéi, HSK7) means 'to flatter' and can carry insincerity.