Number
* mono-: one (monotone, monorail)
* di-: two (dichotomy, dioxide)
* tri-: three (triangle, tripod)
* tetra-: four (tetrahedron, tetralogy)
* penta-: five (pentagon, pentameter)
* hexa-: six (hexagon, hexameter)
* hepta-: seven (heptagon, heptad)
* octa-: eight (octagon, octopus)
* nona-: nine (nonagon, nonagenarian)
* deca-: ten (decade, decapod)
Location
* endo-: within (endocrine, endoskeleton)
* exo-: outside (exoskeleton, exothermic)
* epi-: upon, on (epidermis, epidemic)
* hypo-: under, below (hypodermic, hypothermia)
* hyper-: above, beyond (hyperactive, hyperbole)
* peri-: around (perimeter, periscope)
* para-: beside, alongside (parallel, paradigm)
* pro-: before, in front of (prologue, prognosis)
* syn-: together, with (synthesis, synchronize)
Size
* macro-: large (macrocosm, macroeconomics)
* micro-: small (microscope, microbiology)
* mega-: large (megaphone, megabytes)
Time
* a-: without (amoral, atypical)
* an-: without (anarchy, anonymous)
* ante-: before (antebellum, antecedent)
* post-: after (postmortem, postscript)
* pre-: before (prehistoric, prefix)
* pro-: before (prologue, prognosis)
Direction
* ana-: up, back (anabolic, anagram)
* cata-: down, against (catastrophe, catalog)
* dia-: through, across (diameter, dialogue)
* meta-: change, beyond (metamorphosis, metaphor)
Other
* auto-: self (automatic, autobiography)
* bio-: life (biology, biography)
* geo-: earth (geography, geophysics)
* graph-: writing (autograph, graphic)
* hetero-: different (heterogeneous, heterosexual)
* homo-: same (homogenous, homosexual)
* hydro-: water (hydroelectric, hydrophobia)
* logos-: word, study (biology, psychology)
* meter-: measure (diameter, thermometer)
* path-: feeling, suffering (sympathy, apathy)
* phil-: love (philosopher, philanthropy)
* phob-: fear (hydrophobia, claustrophobia)
* poly-: many (polyglot, polygon)
* tele-: far (telephone, telescope)
* theo-: god (theology, theocracy)
This is just a small sample of the many Greek prefixes in use. Remember that prefix meanings can sometimes overlap, and the meaning of a prefix can be influenced by its context.