The article presents a state-of-the-art complete part-of-speech tagger for Polish using recurrent neural networks. They allow for access
to full left and right context of a sentence in comparison to context window. The tagger uses an external morphological analyzer. In
comparison to the best Polish taggers, it does not use word form as a feature for the classifier, there is no separate classifier for unknown
words and predictions are not limited to tags provided by a morphological analyzer. The obtained accuracy is higher — it achieves 28% error reduction and 7% points higher accuracy for unknown words. The tagger also might work faster than others by utilizing GPU. The
tagger participated in PolEval competition and won two subtasks.