We analyse the difficulty of literature in foreign languages to help you discover texts at your level!

At Interlinear Books, we believe reading fascinating literature is one of the best ways to learn and improve your foreign language skills. To help with this, we have been producing Interlinear (or as we sometimes say: 'subtitled') book translations for language learners. And now, we have created this free literature discovery section where we provide you data about the difficulty of various texts in foreign languages. Try it out right away by choosing a language:

French German Lithuanian Portuguese Russian Spanish Swedish

This tool attempts to help you answer the question: what should I read to improve my foreign language? We believe that it is a hard task for students, teachers and tutors to efficiently locate materials of the appropriate difficulty to support language learning. The tool helps you find and read literature:

• divided by length - the shorter the texts, generally the more manageable they are, thus you get an exact word count and other text length statistics for each text
• evaluated for grammatical complexity - we use various measures of grammatical complexity, such as the Automated Readability Index (ARI) or the Coleman-Liau Index (CLI), Yule's I, Hypergeometric distribution, various textual diversity indexes, as well as corrected and normalised type token ratios (TTR) to determine how difficult texts are
• assessed for the difficulty of vocabulary - we use large frequency vocabulary data and evaluate the lexical complexity of vocabulary used
• often readily available to read and nicely packaged for your reading ease

Here is a rough depiction of what our assessment includes:

We have based our assessment of texts on the algorithms above, many of which have been inspired by scientific research. However, it is worth noting that we cannot guarantee the quality or accuracy of this data and cannot accept responsibility for your use of it, so please take everything with a grain of salt. It is also worth noting that we usually do not provide information about the topics covered in books and reviews of the texts. But we believe that there are plenty of other great sources to find those on that, and, on our part, we want to focus primarily on a language learning perspective.

We intend to keep refining the algorithms and to expand our collection gradually, and also to translate the most interesting and high-quality works to Interlinear!

We suggest you do not hesitate and check out how this works by picking a language above.