The aim of the article is to show that the practice of simplifying texts, referring to the concept of plain language, has long been present in the teaching of Polish as a foreign language. Nowadays, various strategies of text simplification are used for teaching Polish, the most useful of which are: simulation of original texts with the use of graphic materials (especially at levels A1 and A2), text development (by exemplification or paraphrasing) and the technique of text glossing (in the target or intermediary language). An analysis of old textbooks for learning Polish shows that the practice of modifying teaching texts has also been applied in the past. The transformation techniques used formerly concern both the global structure of the text and changes at the word, sentence and paragraph level.