The previous two questions address aspects of this question, as do the earlier questions concerning <gh>. The following lists are of words that contain silent letters from a 6,100 word database of high frequency words. The number in parentheses is the total number of instances in the database, In many cases, inflected and derived forms of words listed below would also contain silent letters – as, for instance, argues, awed, neighborly, biscuits, herbal, honorable, etc. Remember that in my analysis many letters that others might call silent are treated as parts of complex spellings that have evolved due to sound simplification and change – such as the [m] = <mb> in bomb, which others might treat as [m] = <m> with a silent final <b>:
Silent diacritical <e> (1,127): abide, able, above, absence, acknowledge, advertise, argue, awe, bottle, breathe, bronze, cause, crave, etc.
Silent non-diacritical <e> (221): advanced, aisle, ample, anyone, belle, borne, castle, chocolate, come, comrade, concerned, cried, doctine, done, etc.
Silent diacritical <gh> (22): although, bough, eighth, high, neighbor, nigh, plough, sigh, thigh, thorough, though, through, weigh, etc.
Silent diacritical <u> (16): biscuit, catalogue, circuit, disguise, fatigue, guess, guest, guide, guilt, league, plague, rogue, tongue, vague
Silent <h> (12): eh, exhaust, exhibit, heir, herb, honestly, honor, hour, vehicle
Silent <d> (3): handkerchief, handsome, Wednesday
Silent <o> (2): colonel, laboratory
Silent <th> (1): isthmus
Silent <n> (1): monsieur
Silent <i> (1): business