What is the rule?
A silent letter may or may not make its sound based on the spelling.
bomb
bombard
hasten
haste
moist
moisten
resignation
resign
crumb
crumble
muscular
muscle
design
designate
soft
soften
column
columnist
limb
limber
bombard
bomb
haste
hasten
moisten
moist
resignation
resign
crumble
crumb
muscular
muscle
designate
design
soften
soft
columnist
column
limber
limb