Comprise vs Compose: Which One Do You Need?
The whole comprises the parts. The parts compose the whole.
The book comprises ten chapters. Ten chapters compose the book.
The test that settles it
Look at what comes first in the sentence. If the whole is the subject, use comprises. If the parts are, use compose — or the more natural make up.
“The committee ___ nine members” → whole first, so comprises.
“Nine members ___ the committee” → parts first, so compose.
The whole comprises; the components compose.
Comprise: the whole contains the parts
The subject is the complete thing, and what follows is its contents. It takes no preposition.
The estate comprises four houses.
The course comprises six modules.
The set comprises a chair and a table.
Swap in consists of, then remove the of. If the sense holds, comprise.
Compose: the parts make the whole
The subject is the parts. In practice it appears most often in the passive: is composed of.
Six modules compose the course.
The team is composed of volunteers.
Water is composed of hydrogen and oxygen.
Swap in make up. If it works, compose.
Side by side
| Comprise | Compose |
|---|---|
| Whole is the subject | Parts are the subject |
| No preposition | Usually composed of |
| Swaps with consists of | Swaps with make up |
| The whole comprises the parts | The parts compose the whole |
The exception
The team is comprised of volunteers is very common and has been for two hundred years. It is also the single construction most likely to be marked wrong by an editor.
The objection is that comprise already means consists of, so comprised of says of twice. Whether or not you accept that, composed of and consists of are never criticised, so there is no cost to using them.
Where people get it wrong
| Incorrect | Correct | Why |
|---|---|---|
| The book is comprised of ten chapters. | The book comprises ten chapters. | Or: is composed of. |
| Ten chapters comprise the book. | Ten chapters compose the book. | Parts first, so the other verb. |
| The set comprises of two pieces. | The set comprises two pieces. | Comprise takes no of. |
| Water comprises hydrogen and oxygen. | Water is composed of hydrogen and oxygen. | Correct but stilted; the passive reads better here. |
Practice — choose the right word, then check yourself.
- The anthology ___ forty poems.
- Forty poems ___ the anthology.
- The panel is ___ of five experts.
- The flat ___ two bedrooms and a study.
- Volunteers ___ most of the workforce.
Show the answers
1. comprises 2. compose 3. composed 4. comprises 5. compose
Frequently asked
Is comprised of actually an error?
Dictionaries record it; usage guides warn against it. In anything that will be edited, avoid it — composed of costs nothing.
What about consist of?
Always safe, and often the clearest of the three: the course consists of six modules.
More words people confuse
