The Floss Rule
If a one syllable base word end in the /f/, /l/, or /s/ sound immediately after a short vowel, the /f/ sound is spelled ff, the /l/ sound is spelled ll and /s/ sound is spelled ss.
Example: staff hill dress
The Rabbit Rule
One medial consonant sound immediately after a short vowel in a two-syllable base word is spelled with double consonants.
Example: tennis wallet wiggle
The Doubling Rule
If a base word ends in one vowel, one consonant and one accent, double the final consonant before adding a vowel suffix.
Example: rob +er = robber star +ing = starring admit + ed = admitted
The Dropping Rule
If a base word ends in final silent e, drop the e before adding a vowel suffix.
Example: name +ed = named close +ing = closing provide +er = provider
The Changing Rule
If a base word ends in a consonant and a final y, change the y to I before adding a suffix that does not begin with i.
Example: try +ed = tried silly +est = silliest reply +es = replies