It is often r e m a r k e d that natural language, used naturally, is unnaturally ungrammatical.* Spontaneous speech contains all manner of false starts, hesitations, and self-corrections that disrupt the well-formedness of strings. It is a mystery then, that despite this apparent wide deviation from grammatical norms, people have little difficx:lty understanding the non-fluent speech that is the essential medium of everyday life. A n d it is a still greater mystery that children can succeed in acquiring the g r a m m a r of a language on the basis of evidence provided by.
