Interslavic zonal constructed language is an auxiliary language, which looks very similar to real spoken Slavic languages in Central and Eastern Europe and continues the tradition of the Old Church Slavonic language. Interslavic shares grammar and common vocabulary with modern spoken Slavic languages in order to build a universal language tool that Slavic people can understand without any or with very minimal prior learning. It is an easily-learned language for those who want to use this language actively. Interslavic enables passive (e. g. receptive) understanding of the real Slavic languages. Non-Slavic people can use Interslavic as the door to the big Slavic world.