Readability is how difficult or easy it is for the reader to understand the text. A review of the literature revealed that no study had been conducted to determine the readability levels of 17 books prepared for teaching Turkish as a foreign language at A1-C1 levels, and the aim of this study was to calculate the readability levels of these reading books. The case study design, one of the qualitative research methods. The data were analyzed using the descriptive analysis method according to the formulas of Ateşman (1997) and Çetinkaya-Uzun (2010). The results of the study revealed that the basic language level reading books were easy and independent, while the average readability of the intermediate and advanced language level books was at an easy and educational reading level. It was concluded that there was no regular increase in the difficulty level of readability as the language level increased.
Turkish education, teaching Turkish to foreigners, readability, readability formula, reading books.