Rank Scale (grammar hierarchy)

Knowing English grammar will help you write well. One thing you need to notice is rank scale, or grammar hierarchy.

What is a hierarchy? Some people, such as the president of the US, are more important than other people, such as the governors of the 50 states. This is a government hierarchy:

English grammar has another kind of hierarchy. Sentences are more important than phrases (noun phrases and verb phrases), and phrases are more important than words. Finally, words are more important than morphemes (the bottom level: "teachers" is made of three morphemes: TEACH (a "Free" morpheme) + ER (A "Bound" morpheme) + -S).