Subject: comparative methodalexis manaster ramer ask about the claim that relatedness and / or subgroup should be establish only base on systematic morphological relationship of the sort likely to be observe in paradigm or declension . i ' m familiar with this claim only in a much weaker form , that morphological comparison be more reliable than phonological one as a basis for establish linguistic relationship and subgroup . on this basis , for example , robert hetzron in 1976 * propose a rigorous internal subgroup for the semitic language base on affix in the verb paradigm . hetzron 's proposal that hebrew , arabic , and aramaic constitute a central semitic group be , i believe , correct ; and it be support by much more evidence than hetzron adduce , much of it morphological and morpho-syntactic ( e . g . , innovation of novel negative marker , etc . ) . i may be read too much into these claim of morphological priority in establish subgroup , but i have alway interpret them as a reaction to the difficulty of distinguish convergent from share phonological development on a principle basis . that be , because it can be difficult to determine whether a particular recurrent sound change in a language group represent share innovation rather than convergent development , it may be pragmatically safer to rely on morphological innovation . thus , in the case of the semitic language , such change as * p to / f / or * g to / jh / ( as in junk ) would , if treat as share innovation , lead to subgroup that be inconsistent with those deduce by other means . on the other hand , " unusual " change like the change of proto - semitic glottalic consonant to pharyngealize consonant be much more likely to represent share innovation , give the typological rarity of pharyngealize consonant . with regard to fritz newmeyer 's question about comparative syntactic reconstruction , i do n't know of any systematic publish counter to jeffer ' ( and other ' ) claim that it be * in principle * impossible . however , i think that a good case can be make that this be an overly pessimistic assessment . the problem , of course , be the appropriate context : we compare phoneme in word and / or morpheme and morpheme in paradigm , but it 's not clear what the context may be for word order . presumably discourse context play a role . i would imagine that if all the language in a family share an unusual word order ( vi a vi their dominant type , whatever those may be ) in counterfactual , we may want to attribute that order to their latest share ancestor . pragmatically speak , it 's a lot easier to find information about the morphological context of particular phoneme than it be to find reliable information about the larger context for sentence and construction type . nonetheless , at least inchoately ( and perhap it be the inchoateness that jeffer object to ) , * some * notion of syntactic reconstruction be surely behind claim that proto - indo - european be sov or proto - semitic be svo , and the like . * " two principle of genetic reconstruction " , lingua 38 : 89-104 . alouse faber faber @ haskin . yale . edu