In "高兴/地/说", is 高兴 an adjective or an adverb?
The following link is a document on "Part-Of-Speech Tagging Guidelines for the Penn Chinese Treebank (3.0)"
https://repository.upenn.edu/cgi/viewcontent.cgi?article=1039&context=ircs_reports
The Chinese Treebank 8.0 data can be downloaded from https://wakespace.lib.wfu.edu/bitstream/handle/10339/39379/LDC2013T21.tgz?sequence=1
I am building a Chinese part-of-speech tagger model using the Ontonotes corpus, which contains Penn Chinese Treebank data. After reviewing many of the annotated sentences, I fail to understand the annotation of many 'VA' adjectives that precede (的/地(DEV) verb(VV)). I processed the annotated sentences into a file, and by regular expression I found that words in this case are twice more likely to be annotated as VA than to be annotated as AD.
In my impression, regarding "XXX 地 verb", XXX is always an adverb. But in the corpus, hundreds of cases like this are annotated as an adjective, like "可以/VV/O 轻易/VA/O 地/DEV/O 改变/VV/O", ..., etc.
See page 14 of the document. 高兴 seems to be an adverb (AD) instead of an adjective (VA).
Why are the words like this annotated as VA instead of AD? How to tell whether words of this case should be annotated as VA, JJ, or AD ? Or are the part-of-speech tags of the words really correctly annotated in the Chinese Treebank data?