William Dwight Whitney 
Sanskrit Grammar [PDF ebook] 

This Sanskrit Grammar is on a somewhat different plan from those already in use. It presents the facts of the language primarily as they show themselves in use in literature and only secondarily as they are laid down by the native grammarians. It also includes in the presentation the forms and constructions of the older language as exhibited in the Vedas the Brahmanas the Epics and the Puranas. The author has cast all statements classifications, etc; into a form consistent with the teachings of linguistic science.