In-/Im-/Il-/Ir- (not)
In-, im-, il-, ir-
Not. The spelling changes with the next letter.
Rushing your homework can lead to incorrect answers.
Impossible
Not possible.
Climbing the hill in one hour seemed impossible to Sana.
Irregular
Not regular; not following the usual pattern.
'Go' is an irregular verb because its past is 'went'.
Remember: im- before b, m, p (impatient); il- before l; ir- before r. Trap: in- can also mean 'into', so inflammable means 'burns easily'!