Comprise and Compose
To comprise means to consist of (e.g., The cake comprises four slices.) Here are some quirks with to comprise:
- Do not use of with comprise (e.g., It comprises of...
). - Avoid the construction is comprised of.
- Avoid naming the constituent parts first (e.g., Four slices comprise the cake.)
Comprise and Compose
There is often confusion over comprise and compose. The situation is not helped by ongoing debate about how to use comprise. If you stick to the guidelines below, you will be on safe ground.Comprise
To comprise means to consist of or to be made up of. It is used to state that something is made up of smaller parts. Do not use the word of with comprise.Examples:
- The water molecule comprises two atoms of hydrogen and one atom of
oxygen.
(The whole comprises the smaller parts.)
- The water molecule comprises of two atoms of hydrogen and one atom of
oxygen.
(Do not use the word of with comprise.)
- Two atoms of hydrogen and one atom of oxygen comprise the water molecule.
(This is one of the areas under debate. Many advocate that comprise cannot be used to say the smaller parts make up the whole. They believe this is when compose should be used. If you adhere to this ruling too, you will
never be on safe ground.)
- The three wise monkeys comprise Mizaru (see no evil), Kikazaru (hear no evil), and Iwazaru (speak no evil).
- The quadriceps femoris comprise the rectus femoris, the vastus medialis, the vastus intermedius and the vastus lateralis.
Is Comprised Of
The construction is comprised of (it correctly includes the word of) is considered by many to be non-standard English. To avert criticism, reword your sentence to avoid this construction.Examples:
- The water molecule is comprised of two atoms of hydrogen and one atom of oxygen.
(Some of your readers may frown at this version.)
- The water molecule comprises two atoms of hydrogen and one atom of oxygen.
(This is the non-contentious version.)
Compose
To compose means to make up or to make. It is used to state that smaller parts make up the whole (i.e., the opposite of comprise). Do not use the word of with compose.Examples:
- Mercury, Venus, Earth, and Mars compose the inner planets.
- The rectus femoris, the vastus medialis, the vastus intermedius and the vastus lateralis compose the quadriceps femoris.
- Two atoms of hydrogen and one atom of oxygen compose the water molecule.
Is Composed Of
The construction is composed of (it correctly includes the word of) does not attract the same criticism as is comprised ofExamples:
- USA is composed of 50 states.
- The water molecule is composed of two atoms of hydrogen and one atom of oxygen.
A Quick Test
Name All the Constituent Parts
Make sure you name all the constituent parts when using comprise or compose.- Since August 2006 when the International Astronomical Union declassified Pluto as a planet, only eight planets compose our solar system.
(Our solar system also includes the Sun, an asteroid belt
and a number of dwarf planets. Therefore, compose is incorrect in this example.)
Beware Include
Do not name all the constituent parts when using include.- The water molecule includes two atoms of hydrogen and one atom of oxygen.
- The water molecule includes one atom of oxygen.
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