Here is yet another set of verbs that tend to offer a great deal of confusion to writers and readers both. Let’s take a quick look at these two verbs, and get the clear picture on the usage of each.
Comprise — This word hold the same meaning as the phrase, “is composed of” in a sentence. When using this verb it is best to start with the whole unit in which you want to speak. For example: “The puzzle comprises 200 pieces.” I have seen several instances where someone has written the previous example like so: “The puzzle is comprised of 200 pieces.” This would be incorrect, and leads us into the other verb in discussion.
Compose — This means “to be made of”. The previous example could be re-written using this verb to be edited: “The puzzle is composed of 200 pieces.” Or, you could use this verb when starting your sentence with the parts instead of the whole: “Two hundred pieces compose this puzzle.” “Four quarters compose a dollar.”
The best way to remember the difference is the O Rule. In the phrase composed of the letter ‘o’ appears in both words. Also, if you’re starting the sentence with the whole then use comprise. If you’re going to start it with the parts then use compose. I hope this little bit of information helps.