"Compose" = to make up the whole (the parts COMPOSE the whole); "comprise" = to contain or consist of (the whole COMPRISES the parts).
Verb: the parts MAKE UP or FORM the whole. The direction from the subject is parts to whole. "Ten states compose the federation" = ten states MAKE UP the federation. The parts are the subject. Also: to compose music, to write a composition.
Twelve members compose the jury, and all twelve must agree for a unanimous verdict.
The album is composed of seven original tracks and three covers.
Water is composed of hydrogen and oxygen atoms bonded together.
Verb: the whole CONTAINS or INCLUDES the parts. The direction from the subject is whole to parts. "The federation comprises ten states" = the federation CONTAINS ten states. The whole is the subject. CRITICAL NOTE: "comprised of" is generally considered incorrect in formal writing. The rule: "is composed of" OR "comprises" — not "is comprised of".
The committee comprises five elected members and two appointed advisors.
The novel comprises three parts: a prologue, the main narrative, and an epilogue.
The curriculum comprises core courses in mathematics, language, and science.
Common mistake
"Is comprised of" is the most common error with this pair — heard even from educated speakers, but formal style guides flag it as incorrect. Correct forms: (1) "is COMPOSED of" (using "compose"), or (2) "COMPRISES" without "of". "The team is comprised of five players" = INCORRECT in formal writing. "The team is composed of five players" = CORRECT. "The team comprises five players" = CORRECT. Quick rule: if you say "comprised", do not add "of".
Trick to remember it
Think of a CONTAINER (the whole) and its CONTENTS (the parts). COMPRISE: the CONTAINER comprises its contents. "The box COMPRISES six items" = the box CONTAINS six items (the box is the whole, the items are the parts). COMPOSE: the items COMPOSE the box. "Six items COMPOSE the box" = six items MAKE UP the box (the items are the parts that form the whole). The WHOLE COMPRISES the parts. The PARTS COMPOSE the whole.
Quick rule
The whole COMPRISES the parts. The parts COMPOSE the whole. Never "is comprised of" in formal writing — use "is composed of" or "comprises".
Did you know?
"Is comprised of" appears so frequently — even in academic texts and respected publications — that some descriptive linguists argue the construction should now be considered correct by majority use. However, the Chicago Manual of Style, Garner's Modern English Usage, and most university style guides still flag it as an error. It is a perfect example of the conflict between prescriptivism (the rule exists) and descriptivism (the majority ignores it).
Exercise 1 · Pick the right one
The research team _____ twelve scientists from six different countries.
Exercise 2 · Pick the right one
The thirteen original colonies _____ the United States at the time of independence.
Exercise 3 · Form the word
The whole COMPRISES the parts. The parts COMPOSE the whole. Never "is comprised of" in formal writing — use "is composed of" or "comprises".
"Is comprised of" is the most common error with this pair — heard even from educated speakers, but formal style guides flag it as incorrect. Correct forms: (1) "is COMPOSED of" (using "compose"), or (2) "COMPRISES" without "of". "The team is comprised of five players" = INCORRECT in formal writing. "The team is composed of five players" = CORRECT. "The team comprises five players" = CORRECT. Quick rule: if you say "comprised", do not add "of".
Think of a CONTAINER (the whole) and its CONTENTS (the parts). COMPRISE: the CONTAINER comprises its contents. "The box COMPRISES six items" = the box CONTAINS six items (the box is the whole, the items are the parts). COMPOSE: the items COMPOSE the box. "Six items COMPOSE the box" = six items MAKE UP the box (the items are the parts that form the whole). The WHOLE COMPRISES the parts. The PARTS COMPOSE the whole.
Bryan López
Founder of SpeakUP Academy