comparative syntax really like scott delancey say syntactic reconstruction usually based clues buried morphology morphophonology nt think always case rather famous example involving rule ancient greek one variety old iranian languages gatha seem recall whereby neuter pl subject triggers sg agreement verb pattern often reconstructed protolanguage understand apparent oddity reconstruction logically dependent nt believe identity actual morphemes marking gender number person languages would think many quirks syntax could basis reconstruction e g polish several indo european languages show traces pattern whereby np referring group composed males females grammatically neuter playing around idea trying reconstruct old pattern would quite independent particular number morphemes involved b w anyone knows literature phenomenon would grateful references post summary form another example interesting happen know history russian various complicated things case number endings nouns adjectives combined numerals thus nominative case adj n two adj n show different adj noun forms russian presence numeral 2 4 adj looks gen pl form unless feminine either gen pl gen sg possible noun looks like gen sg form except one two nouns seem take special form differing stress placement gen sg closely related polish hand nothing special case though languages weird things numerals 4 need concern us wonder would able conclude behavior ancestor languages distinct paucal number 2 4 paucal category merged plural polish stayed distinct russian hypothesis paucal endings must looked like genitive sg ones even hypothesis might paucal originally dual since paucal unusual category course know happened wonder could reconstructed even known provided syntactic patterns distinctive e g weird enough purely syntactic comparative reconstruction possible bet could even find examples literature besides greek iranian one cited problem seems impossible consider patterns quite prosaic number possibilities small like socalled basic word order talked much discussion even think looked detailed facts word order ov vo like group languages might able reconstruct proto system word order degree confidence even basic order might reconstructable enough enough languages enough diversity geographical dispersion fact classical latin often verbfinal romance languages verbmiddle verbinitial seem important counterexample vernacular latin may well much verb middle literary former relevant b romance languages exhibit much diversity dispersion ex seem clear reconstruct ov proto turkic proto mongolic vo proto polynesian