Top Highlights

• Descriptive grammar gives names to things — the parts of speech and parts of a sentence. When you learn descriptive grammar, you understand what every word is (its part of speech) and what every word does (its function in the sentence).
• Functional grammar tells you how words behave when they are doing their jobs properly. Functional grammar guides you to the right expression — the one that fits what you're trying to say — by ensuring that the sentence is put together correctly.
• these verbs were called copulative, from a root word meaning "join."