about the cause and effect of an action. Furthermore, Saba pointed out that “NLU is, for the most part, a commonsense reasoning process at the pragmatic level” (Saba, 2006). And in his work, some reference must be resolved by recourse to causality knowledge. For instance, in the sentence “Jonh shot a policeman, he immediately fell down”, we could infer that “he” refers to “a policeman” relied on the causal relation “Shot(x,y) Fall_down(y)” .