Tvrdé y/ý and měkké i/í exist in written form in standard Czech, but they have been pronounced in the same way, softly, across most of the country since the late Middle Ages or so. That is why many pupils struggle with "where to write y and where to write i", because it does not correspond to their daily experience with spoken Czech.

An interesting exception is the region around Ostrava, where "y" remained a clearly different vowel in pronunciation until today.