In addition, whereas English has a large treebank, containing over one million annotated words, many other languages have much smaller treebanks, which also contribute to the drop in the accuracies of the data-driven parsers.
the analysis revealed the following reasons for the low impact of the agreement filter: (1) the grammar is strong enough to produce fairly accurate structures, which have very few agreement mistakes to begin with, and 2fixing an agreement mistake does not necessarily mean fixing the entire parse-in some cases it is very easy for the parser to fix the agreement mistake and still produce an incorrect parse for other parts of the structure.