Basic Word Structures of Medical English There are five possible parts to a medical word, which are , , , , and . Of these five parts, the is the foundation of a word. The (word beginning) is what comes before the and the (word ending) is what comes after the . A combining (or connecting) vowel (mostly is an “ o ” ) is a vowel used to combine two or a and a . It does not have any meaning. A combining form is made up of a plus the .