Punctuation Marks in English Grammar Punctuation marks are the symbols we use in writing to separate sentences, clarify meaning, and guide the reader. They help us pause, emphasize, or connect ideas correctly. From the full stop (.) that ends a sentence, to the comma (,) that separates ideas, to the question mark (?) that shows inquiry, each punctuation mark has a specific role. Mastering punctuation not only improves writing clarity but also prevents misunderstandings.