  In this paper we investigated two different methods to parse relative and
noun complement clauses in English and resorted to distinct tags for their
corresponding that as a relative pronoun and as a complementizer. We used an
algorithm to relabel a corpus parsed with the GUM Treebank using Universal
Dependency. Our second experiment consisted in using TreeTagger, a
Probabilistic Decision Tree, to learn the distinction between the two
complement and relative uses of postnominal "that". We investigated the effect
of the training set size on TreeTagger accuracy and how representative the GUM
Treebank files are for the two structures under scrutiny. We discussed some of
the linguistic and structural tenets of the learnability of this distinction.
