Moreover, there are much more different possible morphosyntactic tags in the case of agglutinating languages (corresponding to the different possible inflected forms) than in English (several thousand vs. a few dozen).
data sparseness is threefold: • an overwhelming majority of possible word forms of lemmata occurring in the corpus is totally absent, • word forms that do occur in the corpus have much less occurrences, and • there are also much less examples of tag sequences, what is more, many tags may not occur in the corpus at all.