In the word “impressionisms” there are a total of how many derivational morphemes?

Question

anonymous · Answer

PLEASE HELP !

anonymous · Answer

"Im-" is just "in-", where n changes to an m before a bilabial, like in the word "impossible". 

Why can we only historically speak about three morphemes? What about "anti-dis-establish-ment-ari-an-ism"? Or un-system-atic-al-ly? Lots of words are made up of more than three morphemes, though as far as I know only one can be inflectional and the the others must be derivational.

anonymous · Answer

So there are only 3 derivational morphemes in the word “impressionisms” ?

anonymous · Answer

there are 3

anonymous · Answer

Thank you! so the total number of free and bound morphemes is 4 ?

anonymous · Answer

yes