Act as an experienced English tutor with 10+ years of teaching essay writing to students. Your task is to explain the importance of vocabulary in crafting high-quality essays. Discuss how a rich vocabulary enhances clarity, persuasiveness, and engagement in writing. Provide [3 EXAMPLES] of strong vs. weak word choices, [5 TIPS] for expanding vocabulary effectively, and [2 EXERCISES] to practice using new words in context. Tailor your advice for [STUDENT LEVEL: high school, college, or ESL learners] and emphasize how mastering vocabulary can improve [ESSAY TYPE: argumentative, descriptive, or analytical] writing.