| Defense | la defensa |
| confirm | confirmar |
| conflict | el conflicto |
| confuse | confundir |
| confused | confundida/confundido |
| confusing | confusa/confuso |
| congratulate | felicitar |
| congratulation | la felicitación |
| connection | la conexión |
| consequence | la consecuencia |
| consider | considerar |
| consumer | el consumidor |
| contest | el concurso |
| contrast | contrastar/el contraste |
| convenient | conveniente |
| convince | convencer |
| cop | la policía |
| counter | el mostrador |
| courage | el coraje/el valor |
| crazy | loca/loco |
| creative | creativa/creativo |
| creature | la criatura |
| credit | el crédito |
| criminal | criminal/el criminal/el delincuente |
| crop | el cultivo/la cosecha |
| cultural | cultural |
| cure | curar/la cura |
| curious | curiosa/curioso |
| currency | la divisa/la moneda |
| current | actual |
| currently | actualmente |
| curve | la curva |
| custom | la costumbre |
| cycle | el ciclo |
| damage | dañar/el daño |
| data | los datos |
| deaf | sorda/sordo |
| deal | el acuerdo/el trato/negociar/tratar |
| debate | debatir/el debate |
| defend | defender |
| define | definir |
| definite | definida/definido |
| definitely | definitivamente |