UNCERTAIN
INADEQUATE
INCOMPLETE
INSINCERE
IRRATIONAL
UNABLE
IMPROBABLE
IMMATURE
UNATTRACTIVE
INACCURATE
ILLITERATE
IMPERSONAL
Not good enough, or too small in quantity
No behaving in a way expected of someone your age.
Not likely to happen or to be true
Not good enough to look at
Not complete, not finished
Not using clear thinking or reason.
Not able to read or write
Not correct
With little or no human warmth of interest
Not able to do something
Not really meaning what you say.
Not knowing what to do, not able to decide.