This book constitutes the refereed proceedings of the 20th and 21st International Conference on Formal Grammar 2015 and 2016, collocated with the European Summer School in Logic, Language and Information in August 2015/2016. The 19 revised full papers presented together with 2 invited talks were carefully reviewed and selected from a total of 34 submissions.
The focus of papers are as follows:


Formal and computational phonology, morphology, syntax, semantics and pragmatics
Model-theoretic and proof-theoretic methods in linguistics

Logical aspects of linguistic structure

Constraint-based and resource-sensitive approaches to grammar

Learnability of formal grammar

Integration of stochastic and symbolic models of grammar

Foundational, methodological and architectural issues in grammar and linguistics

Mathematical foundations of statistical approaches to linguistic analysis