| A | B |
| contra-, counter- | against, opposite |
| contraband (n) | against the law to buy or sell |
| contradict (v) | express the opposite |
| contrarian (n) | one who thinks differently from another |
| contrary (adj) | opposite in nature |
| contrast (v) | to observe how things are not related |
| counterbalance (n) | a weight used to balance an opposite weight |
| counterclockwise (adv) | moving opposite the hands on a clock |
| counterexample (n) | an example used to support an opposing claim |
| counterfeit (adj) | fake or artificial |
| counterintuitive (adj) | against common sense |
| sym-, syn- | together, same |
| symbiosis (n) | relationship with 2 organisms that depend on each other |
| symmetry (n) | having the same shape on both sides of the middle |
| sympathy (n) | sharing kindness with one who is suffering |
| symposium (n) | a meeting to discuss a topic |
| symptoms (n) | conditions indicating what is "wrong" |
| synagogue (n) | Jewish meeting place for worship |
| syndicate (n) | group of business people working together |
| synonym (n) | a word meaning about the same as another |
| synthesis (n) | parts put together to make a whole |
| synthetic (adj) | formed together from fake parts |
| co-, com- | together, with |
| coexist (v) | existing peaceably in the same place |
| cohesive (adj) | working together |
| coincidence (n) | happening together, appearing to be planned |
| combine (v) | to put two things together |
| commiserate (v) | to feel pity with another person |
| committee (n) | a group who meet together to plan |
| communication (n) | the act of talking with someone |
| community (n) | a place where people live together |
| compare (v) | noticing the "sameness" of items |
| compatible (adj) | things that go together without problems |
| re- | again, back |
| recheck (v) | look at something again |
| reclosable (adj) | able to be sealed or shut again |
| reelect (v) | to vote one into the same office again |
| refund (n) | money that is given back |
| reimburse (v) | to pay back |
| remember (v) | bring back to mind |
| renew (v) | to make something new again |
| repeat (v) | to say something again |
| respond (v) | to answer another |
| revive (v) | to bring back to life |
| infinitive (inf) | to + a verb (to see) |