Grammar exists to make communication easier. Learning how to improve and master grammar and punctuation may seem tedious and challenging, but it will ultimately determine how you learn English. Despite the multitude of AI tools like ChatGPT and Grammarly that can help you with checking grammar, these tools can only help you so far to form the foundation of communication. Your own knowledge, and what you learn about English and writing it, will determine the quality, style and voice of your own creativity. Welcome to this handbook, designed to help you to develop the knowledge and skills to improve your grammar and punctuation. Aimed at high school students, Grammar Skills Handbook delves into the fundamentals of grammar, such as phrases, clauses, groups, punctuation, open-class words and closed-class words. Through getting a good grasp of grammar, you will unravel the different layers of grammar, starting with understanding the patterns of language, the parts of speech, and lastly, the essential element of written language, also known as the sentence. Knowing how written English works is at the mind and heart of writing and reading.