This volume contains a selection of papers presented at the 10th and 11th Meeting of the Association for Mathematics of Language, held in Los Angeles, CA, USA in July 2007 and in Bielefeld, Germany, in August 2009.The 19 revised papers presented together with 3 invited speeches were carefully selected from numerous submissions. The papers in this collection reflect a wide range of theoretical topics relating to language and computation including papers on the intersection of computational complexity, formal language theory, proof theory, and logic, as well as phonology, lexical semantics, syntax and typology.