The chapters of this book have in common the treatment of linguistic change with emphasis on its role in the formation of Brazilian Portuguese grammar. The authors are well known researchers in the Brazilian and international linguistic scene for their work on instability and language formation. The change is analyzed from approaches that use the postulates of functional linguistics centered in the use, as the classic theory of grammaticalization and the grammar of the constructions, besides the indispensable contributions of the sociolinguistic variations.