comparative method syntax fritz newmeyer asks legitimate apply comparative method syntax answer yes difficult main reason one sees work historicalcomparative syntax fifty years ago syntax become much prestigious recent decades nt think shift standard view syntactic reconstruction impossible bernhard delbrueck historicalcomparative syntax indo european published hundred years ago clearly showed comparative syntax possible fruitful perhaps difficult attract many followers view historicalcomparative syntax impossible defended detail lightfoot 1979 principles diachronic syntax researchers seem discouraged lightfoot attitude true latin syntax could hardly reconstructed modern romance languages neither could latin morphology even view latin phonology would get romance distorted reconstruction protolanguage grammar always imperfect reason attempt reconstruction main error lightfoot side syntactic analog regularity sound change bit complicated syntax like syntax complicated overall phonology basically analog phonemes words words sentences true difference words sentences general sentences stored lexicon neither many complex words rendering morphological reconstruction similarly difficult nobody seems ever objected morphological reconstruction sentences actually stored e g proverbs idioms often show syntactic archaisms since earlier syntax often survives fossilized form later morphology another rich source data diachronic syntax addition regularity change need general principles change plausible reconstruction e g phonological principles predict likely changes like assimilation lenition segment loss etc syntax similar principles change exist well spatial nouns become spatial adpositions certain general verbs become tense aspect markers allative case markers become dative case markers purposive verb forms become infinitives etc processes instances grammaticalization irreversible changes provide safe guides linguists seeking make sense daughter language diversity reconstructing protosyntax massive regularities grammaticalization generally ignored generative studies syntactic change indeed lightfoot argues genuine principles diachronic syntax one takes account help difficult task reconstruction martin haspelmath free university berlin