Do you have a med term book? We were required to buy one and are tested periodically throughout Fundamentals this semester (no actual med term class). We use Mastering Healthcare Terminology by Betsy Shiland, and it defines all the parts of words in chapter 1, then readdresses them in each topical chapter. My entire class passed the first test, so it must be a decent text. From chapter 1, prefixes (they are added in front of the root) include: ante-, anti-, dys-, endo-, ex-, hyper-, hypo-,... and suffixes include -al, -ectomy, -graphy, -itis, -logy, -scopy, -y. You don't always have both a prefix and a suffix, but you need at least one. The root of the word is in between the prefix and suffix, and you use its "combining form" - arthr/o, cardi/o, colon/o, enter/o, etc. The vowel after the "/" is the combining vowel. Hope that helps, and you may want to invest in another book if you're really not getting it.