Non-English language publications in Citation Indexes -- quantity and quality

We analyzed publications data in WoS and Scopus to compare publications in native languages vs publications in English and find any distinctive patterns. We analyzed their distribution by research areas, languages, type of access and citation patterns. The following trends were found: share of English publications increases over time; native-language publications are read and cited less than English-language outside the origin country; open access impact on views and citation is higher for native languages; journal ranking correlates with the share of English publications for multi-language journals. We conclude also that the role of non-English publications in research evaluation in non-English speaking countries is underestimated when research in social science and humanities is assessed only by publications in Web of Science and Scopus.