A (on)
Mean: On, in
Ex: aboard, asleep
A (out)
Mean: Out, from
Ex: awake, alight
Be
Mean: By ( sometimes intensive)
Ex: beside, betimes
For
Mean: thoroughly
Ex: forbear, forgive
Fore
Mean: before
Ex: forecast, foretell
Gain
Mean: against
Ex: gainsay
In
Mean: in
Ex: income, inland
Mis
Mean: wrong, wrongly
Ex: mislead, misjudged
Over
Mean: above, beyond
Ex: overcharge, overflow
To
Mean: this
Ex: today, tonight
Un (not)
Mean: not
Ex: untrue, unkind, unholy
Un ( to reverse an action)
Mean: to reverse an action
Ex: untie, undo, unfold
Under
Mean: beneath, below
Ex: undercharge, underground
With
Mean: against, back
Ex: withdraw, withstand, withhold