So the question is that if the morpheme, {-able}, is considered a bound morpheme, however, I am not sure why it cannot be used by itself and be considered a free morpheme, i.e. I am able to do this. Also, it is pronounced, ible and not able. But why?


  • 2
    It's pronounced -ible and not able because it's a suffix, not a free morpheme. Suffixes are often pronounced in ways different from lexical words. And it's a bound morpheme because when it's pronounced this way it's always attached to something, and never appears free. The fact that it's often spelled the same as the adjective able doesn't make it the same morpheme; it's never pronounced the same. Also, the suffix, but not the lexical item, is often spelled -ible, not -able, though it's pronounced the same however it's spelled. Oct 1, 2018 at 0:29

1 Answer 1


The word “able” is certainly a free morpheme. The relevant question is whether “able” and “-able” represent the same morpheme. The identical spellings are actually somewhat of a coincidence, as they have different etymologies. The “-ble” parts have the same origin, but the A's don't: the word able is from Latin hăbĭl-, which came from the verb hăbeo + the suffix -bĭl- (one of the B's was apparently lost by haplology), while the suffix -able is from Latin -ābĭl-, which came from the suffix -bĭl- combined with the A-vowel that occurred at the end of "first-conjugation" verb stems.

But I don’t think etymology by itself is a full explanation for why “-able” would be analyzed as a different morpheme from “able”.

I think it’s relevant that the distribution of “-able” looks like the distribution of a bound morpheme/affix: there are words where it triggers a (sometimes optional) stress shift, such as “preferable”, and there are words where it combines with a bound morpheme, or at least a specialized allomorph that cannot occur freely, such as “despic-“ in “despicable”.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.