Like the element ad-, com- does not create new words in English, but it appears in many familiar words under a variety of spellings. The basic meaning of the prefix com- is “together, with.” It comes from the Latin prefix com-. Before the consonants l and r, Latin com- became col- and cor-, respectively, as we see in our words collaborate and correspond. Before all other consonants except p, b, or m, com- became con-, as in confirm, constitution, and contribute.
