My question is simple, is there a known reason why the word “prefix” has only one “f” but the word “suffix” has two, “ff”?
Answer
These words are ‘borrowed’ from Latin, which routinely performed elision and assimilation on prefixes with a final consonant when the consonant was sufficiently similar to the initial consonant of the root to which it was attached. The resulting word was spelled with a doubling of the remaining consonant.
pre- + fix- … no final consonant, so prefix
sub- + fix- … so suffix
ad- + fix- … affixin- + toler- … {n} and {t} are very high contrast, so intolerant
in- + med- … immediate
in- + lum- … illuminate
The same pattern is followed with modern coinages using Latin prefixes and roots.
Attribution
Source : Link , Question Author : ElektroStudios , Answer Author : StoneyB on hiatus
