It is worth remembering that rarely do we spell orally (by the mouth, that is) after we leave school. When we spell, we do it in letters, bills, and compositions.
From this it follows, that spelling should always be taught by writing. If you can spell correctly on paper, you can spell correctly with the voice, when you need to do so. Much of the time spent in this study (nay, in all our school-studies, for that matter) is wasted. Children should always spell (after they learn to write, and that should be early) with pen or pencil in hand. Every minute so spent will be so much clear gain, and the lesson can never be forgotten. James A. Page, the veteran teacher at the Dwight School, Boston, used to write the following lists of words on the blackboard, to straighten us out on the ie and ei.
IE
Believe
Besiege
Relieve
Retrieve
Reprieve
EI
Perceive
Receive
Conceive
and
Deceive
One, certainly, can testify that the lesson has continued in mind to this day.