Eduardo D. Faingold 
Development of Grammar in Spanish and The Romance Languages [PDF ebook] 

Researchers in Romance languages will find this book a stimulating and broad-ranging treatment of the development of grammar, demonstrating the relevance of markedness for both linguistic theory and language teaching. A substantial and original account of a unique body of data, across first and second language acquisition, creolization and historical linguistics and across a wide range of languages and contact varieties, demonstrates a new impetus and predictive force for markedness theory.