When is the b silent?

Answer 1

The B is usually silent during an MB bond, especially at the end of a certain syllable or word like bomb, comb, tomb, womb, dumb, crumb, limb, climb, lamb, thumb, numb, etc. or if there a BT bond at the end of a certain syllable or word like debt, doubt, etc. When you see an MB or BT bond, the B is not always silent and there's still some cases when the B is pronounced. When the MB and BT bond is at a separate syllable like Cambridge, Cambrian, amber, chamber, slumber, obtain, subtract, subtitle, etc., then that's when the B is still pronounced in these bonds. However, there are some rule-breaker exceptions like "subtle", which the B is silent despite the BT bond is at a separate syllable, not at the end of a certain syllable or word.

Answer 2

The "b" is typically silent when it comes after "m" at the end of a word, such as in words like "comb" or "thumb."