When a base or suffix ends in silent <e>, drop the <e> before adding a suffix which begins with a vowel.
Here are some suffixes that begin with a vowel: <-ed> <-er> <-ing> <-en> <-ous>
When a base or suffix ends in <-ce> or <-ge>, keep the <e> when adding <-ous> or <-able>.
Here is an example: change + able —> changeable
The suffix <-ful> is not the word <full> — it only has one <l>.
Please look very carefully at this example and figure out what has been done. help + ful —> helpful
Remember that if <-ly> is added to a word ending in <-ful> , the word has two <l>s, as in helpfully and carefully.
The 1+1+1 rule: In many bases of one syllable ending in one consonant with one vowel before it, double the final consonant before adding suffixes which begin with a vowel, such as <-ed>, <-er>, <-est>, or <-ing>.
Look at these examples: rob + er —> robber run + ing + running
NB: Remember that the final consonant is not doubled when it is preceeded by two vowels or another consonant, such as:
feel + ing —> feeling halt + ing —> halting
NB: Never double the final letters <w>, <x>, and <y>:
snow + ed —> snowed box + ing —> boxing play + er —> player
Words ending in <y>
When a base ends in a consonant followed by a <y>, you change the <y> to <i> before adding a suffix such as:
<-ed>, <-er>, <-est>, <-ment>, <-ly>, or <-age> Please look very carefully at this example and figure out what has been done. cry + ed —> cried
If the letter before a final <-y> is a vowel, the <-y> doesn’t change when you add a suffix:
play + ed —> played
The <-y> doesn’t change before suffixes beginning with <-i>
such as <-ing>: carry + ing —> carrying
NB: When a base ends in <-y> and is preceded by a consonant, to make the plural you change the <y> to <i> before adding <-es>.
Here is an example: lady + s —> ladies
NB: Remember, for bases ending in a vowel and a <y> you keep the <y> before adding <s> to make the plural,