However, this doesn't apply to all words. Example: newer, fewer, slower.
You suggest the following: 1. after short vowels we double the last letter: thin; thinner than; the thinnest
How do you teach students to tell the difference between short and long vowels without necessarily checking the dictionary every time they speak?
We have only five short vowels in English a e i o and u.
These occur mostly between two consonants: pat, pet, pit, pot, cut.
This means that new and slow are not 'short vowels'.
But remember that there are virtually no rules of English spelling that do
not have exceptions:
bus, gas and focus do not double the s in plurals and 3rd person singular: buses, gases, focuses.
That is illogical, and the result is that when they write about busing scholars to different areas, it's a very strange looking word.
This little rhyme shows how illogical the spelling is:
Those who write buses and gases with two esses are asses.
With longer words, doubling the consonant depends on where the accent is. If it is on the last syllable, the consonant is doubled:
infer > inferred
occur > occurred
submit > submitted
allot > allotted
but if it isn't on the last syllable, the consonant isn't doubled:
enter > entered,
banter > bantered
benefit > benefited
worship > worshipped
kidnap > kidnapped (US –p-)
So, for short words, your students just have to know the 5 short vowels, and those are the ones that double the consonant.
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