Prefixes

Letters added to the beginning of a word are called prefixes.
A prefix usually changes the meaning of a word (a suffix usually 
changesthe grammatical function of a word). The word to which 
the prefix or suffix is added is called the base or root.

 
Here is a list some common prefixes  

a- (or -an) 
  Not or without
ab- (or abs-) 
 Away from
ad- 
   Toward, to, or near
ante- 
 Before
anthropo- 
 Man
anti-  
Against
auto-  
 Self
bi-  
  Two
circum-  
   Around
con- ( or com-)  
 with, together
contra- ( or counter)  
Against
de-  
     Do the opposite of, or undo
de-  
     Remove
dis-  
    Not, or do the opposite of
epi-  
    Upon or beside
ex-  
     Out, or from
hydro-  
              Water
in- 
       Not
in-  
      In or on
inter-  
 Between
intra-  
 Within
intro-  
 Into
mal-  
   Bad, or ill
mega-  
Big
micro-  
              Little
mid-  
   Middle
mis-  
   Wrong or wrongly
mono-  
Single, or one
multi-  
Many
non-  
   Not
omni-  
 All or everywhere  
out-  
   Greater or better than
out-  
   At a distance, away
over-  
 Above or over
over-  
 In excess
per-  
   Through
photo-  
Light
pre-  
   Before
post-  
  After
re-  
     Again
semi-  
 Half or part
sub-  
   Below
super-  
              More or bigger than usual
tele-  
  Distant
un-  
     Not, or do the opposite of
uni-  
    Single, or one

 

 
Note that the prefix  In-  becomes  

il-  
before a base beginning with l  
 illegal,
Ir-  
 before a base beginning with r  
 irreversible,   
Im-  
  before a base beginning with m, b, or p  
 impatient, imbecile, impure

 

List of common roots taken from 
Greek and Latin with their basic meaning  


ced ( or cess)  
   Give in, go

cred  
   Believe
curr ( or curs)  
  Run
dict  
    Speak
duc ( or duct)  
   Lead
equ  
    Equal
fract  
  Break
fer  
     Carry, bear
graph 
    Write, print, draw