A-
An- (before vowel or h)
Not
Without
Lacking
Deficient
Anti-
Ant- (before vowel or h)
Against
Opposed to
Preventing
Relieving
Dys-
Bad
Difficult
Painful
Defective
Abnormal
Hyper-
Over
Above
Excessive
Beyond normal
Hypo-
Hyp-
Less than
Below
Under normal
Deficient
Para-
Par- (often before vowel)
Beside
Beyond
Near
Alongside
Abnormal
Irregular