When to Use Comprise vs Compose

Many authors misuse the word comprise in their writing, including scientific and medical writers. They erroneously follow comprise with of, confusing the word with compose.

Comprise means to include or be made up of.

Compose means to form by putting together or to constitute.

Example 1:

The complex comprises three proteins.

The complex is composed of three proteins. 

Example 2:

The solution comprises four chemicals.

The solution is composed of four chemicals.

How can you remember which word to use? A good flag is when you are tempted to follow comprise with of. It will help you remember that the whole comprises the parts, while the parts compose the whole.

The English language constantly evolves, so we may see this rule change. But until then, show your reader that you have mastered the difference between comprise and compose.