3 427 innateness time leap side fence change innateness significance linguistic theory itselt limitations inate abilities mathematical linguistic limit types linguistic theories plausibly constructed processing grammatical structures real time one example course know almost nothing capacity human beings regard slightly less know universals language grin still extent acquire information inate capacity language assuming exist help direct energies proper direction course start talking limits capacity ought clear picture sorts linguistic phenomena involved spoken language dreaded descriptivism eric schiller department linguistics univ chicago