maybe you mean "silent letters" here are some examples:
A - artistically, logically, musically, romantically, stoically
B - climb, comb, crumb, debt, doubt, numb, plumb, subtle, thumb, tomb,
C - acquire, acquit, blackguard, czar, muscle, scissors, victual
D - handkerchief, Wednesday
E - When added to the end of a word, it changes the pronunciation of the word, but is in itself, silent.
F - halfpenny
G - align, alight, champagne, diaphragm, gnash, gnaw, high, light,reign, though,
H - choir, exhaust, ghost, heir, hour, khaki, thyme
I - business
K - blackguard, knead, knell, knickers, knife, knight, knock, knot, know
L - calf, calm, chalk, folk, half, psalm, salmon, talk, yolk
M - mnemonic
N - autumn, chimney, column, condemn, damn, hymn, solemn
O - colonel - opossum
P - corps, coup, pneumonia, pseudo, psychology, ptomaine, receipt
R - butter, finger, garden, here, myrrh
S - aisle, apropos, bourgeois, debris, fracas, island, isle, viscount
T - asthma, ballet, castle, gourmet, listen, rapport, ricochet, soften, thistle
U - catalogue, colleague, dialogue, guess, guest, guide, guilt, guitar, tongue
W - answer, sword, two, whole, whore, wrist, writ, write
X - faux pas
Z - laissez-faire, rendezvous