**Abstract:** We investigate the readability classification of English and German reading materials for language learners based on a broad linguistic complexity feature set supporting the parallel analysis of both German and English. After illustrating the quality of the cross-lingual feature set by showing that it yields state-of-the-art classification performance for the established OneStopEnglish corpus (Vajjala & Lučić, 2018), we introduce the Spotlight corpus. This new data set contains graded reading materials produced by the same publisher for English and German, which supports an analysis comparing the linguistic characteristics of texts at different reading levels across languages. As far as we are aware, this is both the first readability corpus for German L2 learners, as well as the first corpus with comparably classified reading material for learners across multiple languages.
After discussing the first results for a readability classifier for German L2 learners, we show that the linguistic complexity analyses for the cross-language experiments identify features successfully characterizing the readability of texts for language learners across languages, as well as some language-specific characteristics of different reading levels.
