Prefixes add to meaning of original word to make new words.
prefix Example
co- cooperation
dis- disease
dis- dislike
in- inaction
un- unhappy
re- replay-return
tele- television, telephone
trans- transplant
under, sub- underwater, subway
The following Prefix examples are only used with nouns;
auto ( self ) – autobiography, autograph
cyber – cyberwar, cyberspace
semi- semi-professional
non- non-smoker, nonsense
e- email, e-school
mega- megastar, megabyte
ex- ex-husband
mono – monopoly
self- self-study, self-confidence
micro- microscope
mini minicap, minibus
Some examples of prefixes that add negative meaning;
ir- irrelevant
im-impossible
il-illogical