Take the 2-minute tour ×
English Language & Usage Stack Exchange is a question and answer site for linguists, etymologists, and serious English language enthusiasts. It's 100% free, no registration required.

in -> inner

out -> outer / (outter?)

What is the history or set of rules behind why 'inner' doubles the 'n' but 'outer' doesn't double the 't'?

share|improve this question
If the n were not doubled, you would get iner, as in liner, which would be intelligible; hence, the double n. –  Jimi Oke Apr 2 '11 at 1:26

1 Answer 1

up vote 17 down vote accepted

Many English words have a double consonant when following a short vowel. Consider "biter" and "bitter": the double-t signals that the vowel should be the short i vowel. Thus, you write "inner".

For "outer", "out" is already a two-letter vowel, so it doesn't change sound when you add on other letters at the end, hence "outer".

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.