Learning Spanish prefixes is particularly easy for those of us who speak English, because nearly all the common prefixes are the same in both languages. We get most of our prefixes from Greek and Latin, and those were carried over into Spanish as well.
There aren't any real secrets to learning prefixes. Just remember that if you think you know what a prefix means you're probably right. Here are some of the most common ones, along with examples:
- ante- (before): antemano (beforehand), anteayer (day before yesterday), antebrazo (forearm), anteponer (to put something before something else)
- anti- (against): anticuerpo (antibody), antimateria (antimatter), anticoncepción (contraception)
- auto- (self): autodisciplina (self-discipline), autogestión (self-management), automóvil (automobile)
- bi-, bis-, biz- (two): bicicleta (bicycle), bilingüe (bilingual), bisemenal (twice a week)
- cent- (hundred): centímetro (centimeter), centenar (group of 100)
- contra- (against): contraataque (counterattack), contrapeso (counterweight), ir contrareloj (to work against the clock)
- con- (with): convivir (to live together), conjuntar (to coordinate), complot (conspiracy)
- des-(undo, diminish): desplegar (to unfold), desdecirse (to go back on one's word), descubrir (to discover or uncover)
- entre-, (between, among): entremeter (to place among), entrecruzar (to interweave), entreabierto (half-open)
- ex- (former, outside): excombatiente (military veteran), exportar (to export), exprimiar (to squeeze or sqeeze out)
- homo- (same): homónimo (homonym), homólogo (equivalent), homogeneizar (to homogenize)
- im-, in- (opposite): incapaz (incapable), inaudible (inaudible), inconformista (nonconformist)
- inter- (between, among): interacción (interaction), interrumpir (to interrupt), interponer (to interpose)
- mal- (bad): maltratar (to abuse or mistreat), malpensado (malicious), malvivir (to live badly)
- mono- (one): monótono (monotonous), monopolio (monopoly), monocarril (monorail)
- para- (together, with, for): paramédico (paramedic), paraguas (umbrella), parachoques (vehicle bumper)
- poli- (many): poligloto (multilingual person), politeísta (polytheistic), poligamia (polygamy)
- pre- (before): prefijo (prefix), predestinación (predestination), prehistoria (prehistory)
- pro- (in favor of): proponer (to propose), pronombre (pronoun), prometer (to promise)[/td]
- re- (again, with intensity): repaso (review), renacer (to be reborn), renegar (to strongly deny)
- semi- (medium, half): semidifunto (half-dead), semifinalista (semifinalist), semicírculo (semicircle)
- seudo- (false): seudónimo (pseudonym), seudociencia (pseudoscience)
- sobre- (excessive, extraordinary): sobrevivir (to survive), sobredosis (overdose), sobrecargar (to overload)
- super- (superior): supermercado (supermarket), superhombre (superman), supercarburante (high-grade fuel)
- sub- (under): subsuelo (subsoil), subyacer (to underlie), subsector (subsection)
- tele- (at a distance): teléfono (telephone), telecontrol (remote control), telescopio (telescope)
- uni- (one): unificación (unification), unilateral (one-sided), unisexo (unisex)
There are many other prefixes that are less common. Many of the words listed above have additional meanings.
A few of the suffixes — such as seudo-, super- and mal- — can be freely applied to coin words. For example, someone who doesn't study much might be called a seudoestudiante.
http://spanish.about.com/od/spanishvocabulary/a/spanishprefixes.htm