This paper presents our experience with the lexico-semantic annotation of the Prague Dependency Treebank (PDT). We have used the Czech WordNet (CWN) as an annotation lexicon (repository of lexical meanings) and we annotate each word which is included in the CWN.
Based on the error analysis we have performed some experiments with modification of the annotation lexicon (CWN) and consequent re- annotation of occurrences of selected lemmas. We present the results of the annotations and improvements achieved by our corrections.