Basque (was RE: Conlanging guide)

Tim May writes:
 > Christopher Wright writes:
 >  >
 >  > That reminds me, does anyone know of a natural ergative language?
 >  >
 >
 > Basque? (I mean, I know it's ergative, but I don't know _how_ ergative
 > it is.  I've heard that there are no _purely_ ergative natlangs.)

Incidentally, there's a Basque grammar online here

http://www.ehu.es/grammar/

in case anyone wants to, say, prove that all conlangs are ultimately
descended from it.

If anyone knows where there's a grammar of Navajo online, or any
detailed discussion of Mapudungu(n) in English, I'd be obliged to hear
of it.