Language Aspects -- An Evaluation Framework for Controlled Natural Languages -- Rhetorical Compositions for Controlled Natural Languages -- Anaphora Resolution Involving Interactive Knowledge Acquisition -- Talking Rabbit: A User Evaluation of Sentence Production -- Naturalness vs. Predictability: A Key Debate in Controlled Languages -- Implementing Controlled Languages in GF -- Polysemy in Controlled Natural Language Texts -- Economical Discourse Representation Theory -- Controlled English Ontology-Based Data Access -- SBVR's Approach to Controlled Natural Language -- Tools and Applications -- The Naproche Project Controlled Natural Language Proof Checking of Mathematical Texts -- On Designing Controlled Natural Languages for Semantic Annotation -- Development of a Controlled Natural Language Interface for Semantic MediaWiki -- A Controlled Language for the Specification of Contracts -- Rabbit to OWL: Ontology Authoring with a CNL-Based Tool -- Writing Clinical Practice Guidelines in Controlled Natural Language -- What Are Controlled Natural Languages? -- On Controlled Natural Languages: Properties and Prospects.

Controlled natural languages (CNLs) are subsets of natural languages, obtained by - stricting the grammar and vocabulary in order to reduce or eliminate ambiguity and complexity. Traditionally, controlled languagesfall into two major types: those that - prove readability for human readers, and those that enable reliable automatic semantic analysis of the language. [. . . ] The second type of languages has a formal logical basis, i. e. they have a formal syntax and semantics, and can be mapped to an existing formal language, such as ?rst-order logic. Thus, those languages can be used as knowledge representation languages, and writing of those languages is supported by fully au- matic consistency and redundancy checks, query answering, etc. Wikipedia Variouscontrollednatural languagesof the second type have been developedby a n- ber of organizations, and have been used in many different application domains, most recently within the Semantic Web. The workshop CNL 2009 was dedicated to discussing the similarities and the d- ferences of existing controlled natural languages of the second type, possible impro- ments to these languages, relations to other knowledge representation languages, tool support, existing and future applications, and further topics of interest.