1. accidentally or accidentaly ?
This is a word almost everyday we use.
But many of us get confused over the right spelling.
Now the rule to remember here is:
1. If the word ends in one 'l', keep the final 'l' before a suffix beginning
2. If the word ends in double "ll" drop one "l" before a suffix .
accidental = accidental+ly = accidentally (Rule No.1 is applicable here)
full = ful+ly = fully (Rule No.2 is applicable here)
hill = hil+ly = hilly (Rule No.2 is applicable here)