We make mistakes in words that have CH or H [fricative h] because there is no difference in pronunciation. The same issue is caused by sound ʐ because it can be represented by RZ or Ż. Another set of letters pronounced the same way but spelt differently is Ó and U.
These are the most common spelling mistakes.
We do not confuse Ź and Z or Ż - these are three different sounds for us and we don't have any problem to distinguish these sounds. At the beginning of elementary education Polish kids make same mistakes when they spell words with Ś and SI/ Ź and ZI, Ń and NI, Ć and CI, DZI and DŹ - these sounds are almost identical, but there are rules that help in spelling and the more they read and write, the less confusing it becomes.
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