This study considers the performance of tone pronunciation and morpheme intelligibility by L2 Polish Mandarin learners. A mixed-effects ordinal regression model and Tukey's HSD multiple test were used to examine the start-point, end-point, of syllables as a means of assessing their intelligibility by L2 Polish learners regarding the tones with the sequence T0, T1, T2, T4 > T3 and T0, T1> T2, T4 > T3, respectively. Students' tone pronunciation at different stages of learning was compared, i.e. first at less than A1 level of proficiency and then after achieving an A2 level of proficiency according to the Common European Framework of Reference for Languages (CEFR), with the interval of a 22-week intensive Chinese class. The results suggest that in the case of the steady pitch produced for T0 and T1, L2 Polish learners found it easy to control the vibration speed of the vocal folds over two stages. Additionally, progress in successfully producing T4 was exhibited with improving control over the individual tonal register span, implying that competent tonal production develops with time. It remains unclear whether the reason why the low-range T3 is acquired last is down to the habitually high pitched range of spoken Polish, or a more universally observable phenomenon where T3 is liable to be confused with other tones in production.