Unstressed vowels

An unstressed vowel flattens to the same sound whatever letter spells it, so the ear cannot tell them apart. A relative that stresses the syllable gives the letter back.

Say definite, grammar or competition at normal speed and the letter in doubt sits in a weak syllable: defin-I-te, gramm-A-r, comp-E-tition. That murmur, called schwa, can be spelled by almost any vowel letter, so the ear has nothing to choose with.

A related word that puts the stress on the same syllable lets you hear the letter: definite has definition, grammar has grammatical, competition has compete, preparation has prepare. The vowel you can hear in the relative is usually the one the weak syllable keeps.

The same effect is behind the -ance or -ence, -ant or -ent, and -ary, -ery or -ory endings, which have hubs of their own.

The trick needs a relative that moves the stress to the right syllable, and some words do not have one. Separate is the best-known case: separation and separable keep that vowel just as weak, so sep-A-rate is learned with the word.

And a relative can stress the wrong syllable. Check that the vowel you hear is in the same position as the one you are unsure of.

Spelling a word from its relatives is reasoning from meaning, which the research on word structure finds worth teaching. That research is on how people learn to spell.

• Double letters
• Silent letters
• Same sound, different letters
• Silent E
• I before E
• -able or -ible
• -ance or -ence
• -ant or -ent
• -tion or -sion
• -ary, -ery or -ory
• -cede, -ceed or -sede

All spelling traps and origins