Prefixes are the parts that come at the front of a word, suffixes are the parts that come at the end of a word, and roots are the parts that lie in the middle of a word. Think of roots as the base of the word and prefixes and suffixes as word parts that are attached to the base.
These basic word parts generally have the same meaning in whatever word they’re used. For instance, pro- means something along the lines of in favor of, forward, or positive, whether you use it in the word proton or the word proceed.
Each list below has the word part, its meaning, and one word that uses each word part. Write down additional words that use each word part to help you memorize the list. Here is a list of prefixes you should know.| Prefix | Meaning | Sample Word |
| a- | no, not | atheist |
| ab- or abs- | away, from | absent |
| anti- | against | antibody |
| bi- | two | bilateral |
| circum- | around | circumnavigate |
| com- or con- | with, together | conform |
| contra- or counter- | against | contradict |
| de- | away from | detour |
| deca- | ten | decade |
| extra- | outside, beyond | extracurricular, extraordinary |
| fore- | in front of | foreman |
| geo- | earth | geology |
| hyper- | above, over | hyperactive |
| il- | not | illogical |
| mal- or male- | evil, bad | malediction |
| multi- | many | multiply |
| ob- | blocking | obscure |
| omni- | all | omnibus |
| out- | external | outside |
| que-, quer-, or ques- | ask | question, query |
| re- | back, again | return |
| semi- | half | semisweet |
| super- | over, more | superior |
| tele- | far | telephone |
| trans- | across | transatlantic |
| un- | not | uninformed |
| Suffix | Meaning | Original Word: Suffixed Word |
| -able or -ible | capable of | agree: agreeable |
| -age | act of | break: breakage |
| -al | relating to | function: functional |
| -ance or -ence | instance of an action | perform: performance |
| -ation | action, process | liberate: liberation |
| -en | made from | silk: silken |
| -ful | full of | help: helpful |
| -ic | relating to, like | alcohol: alcoholic |
| -ical | possessing a quality of | magic: magical |
| -ion | result of, act of | legislate: legislation |
| -ish | resembling | child: childish |
| -ism | belief in | Buddha: Buddhism |
| -ist | one who characterizes | elite: elitist |
| -ity | quality of | specific: specificity |
| -less | not having | child: childless |
| -let | small one | book: booklet |
| -man | relating to humans | gentle: gentleman |
| -ment | act or process of | establish: establishment |
| -ness | possessing a quality | good: goodness |
| -or, -er | one who does a thing | orate: orator |
| -ous | state of | danger: dangerous |
| -y | quality of | taste: tasty |
If you memorize prefixes, suffixes, and roots, you have a better chance of figuring out the meaning of an unfamiliar word when you see it on the ASVAB. Figuring out the meaning of unfamiliar words is how people with large vocabularies make them even larger. (They look up words in the dictionary, too.)