My research was aimed at discovering the behaviour of internally caused verbs in Hungarian in comparison with the English verbs of this class. The results of the syntactic tests showed that the majority of internally caused verbs are unergative just like their English counterparts. However, there were some problematic cases: some verbs passed only one unaccusativity test but resisted all the other ones. In these cases I propose that these verbs should have two entries in the lexicon: an unaccusative one and an unergative one. Furthermore, there were some verbs with unaccusative behaviour in the majority of verb classes.