predicate-argument structure, as features for the classifiers (Llorens et al., 2010;Laokulrat et al., 2013;D'Souza and Ng, 2013).
the evaluation results of TempEval-3 (UzZaman et al., 2013) show that a system with basic morphosyntactic and lexical semantic features, such as ClearTK (Bethard, 2013), is hard to beat even if using more sophisticated semantic features.