[…] Heb. '‘iּr' ‘city’and '‘aּriּm' ‘cities’ contain different morphemes. Since the difference between '‘iּr' and '‘aּr-' is not found between other morphemes with identical meanings, it seems awkward to state it in a morphophonemic formula: /i/ is replaced by /a/ in '‘iּr' before '–iּm'. Some linguists have called such pairs morpholexical alternants of one morpheme.
- Harris (1942a), Pag. 170