Book excerpt: A Grammar of Bjokapakha by Selin Grollmann constitutes the first description of Bjokapakha, an endangered language spoken in central Bhutan belonging to the Tshangla branch of Trans-Himalayan. This grammar comprises a description of the phonology, lexicon, nominal morphology, predicate structures and syntax. In addition to the descriptive parts, this book encompasses a historical-comparative account of Bjokapakha. The introductory chapter provides a comparison with the standard variety of Tshangla and corroborates the internal diversity of the Tshangla branch. The present-day structure of Bjokapakha verbal morphology is illuminated by means of an internal reconstruction. Moreover, this book contains a glossary and a text collection.