Silent letters occur in spelling but are not pronounced. They can be useful as examples to demonstrate the sometimes inconsistent relationship between English spelling and pronunciation. Silent letters can also be valuable components of introductory lessons to remind new cuers to think beyond spelling when practicing words.
bomb, bombing, climb, comb, crumb, debt, doubt, dumb, lamb, limb, thumb,
autumn, column, condemn, gnash, gnaw, reign, resign, sign, solumn,
knead, kneel, knew, knight, knock, knot, know, knowledge
psalm, pterodactyl, psychiatry, psychology
castle, nestle, rustle, thistle
wrench, wrestle, wriggle, wrist