According to the official adult literacy report conducted in 24 highly-developed countries, more than 50% adults, on average, can only understand basic vocabulary, short sentences, and basic syntactic constructions. Everyday information found in news articles is thus inaccessible to many people, impeding their social inclusion and informed decisionmaking. Systems for automatic sentence simplification aim to provide scalable solution to this problem. In this paper, we propose new

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... sentence simplification systems for English and Spanish, and specifications for expert evaluation that are in accordance with well-established easyto-read guidelines. We conduct expert evaluation of our new systems and the previous state-of-the-art systems for English and Spanish, and discuss strengths and weaknesses of each of them. Finally, we draw conclusions about the capabilities of the state-of-the-art sentence simplification systems and give some directions for future research.