Medical Decoder: Prefixes, Roots & Suffixes

Cardi + o + logy needs a bridge — say "cardilogy" out loud and hear why. Greek and Latin word-parts almost never end and begin with vowels that sit naturally together, so a linking vowel gets dropped in purely to keep the word pronounceable.

It's not decoration. Pull it out and the word collides into an unpronounceable cluster; put it in, and two solid word-parts click together cleanly — the same job as the space between two spoken words, just glued in instead of left open. O is the most common one in medical terms, but i, e, and a all pull the same duty elsewhere.

Sometimes the vowel disappears entirely instead — that's a different trick called elision, and it's why circulate + -ory becomes circulatory, not circulateory.