When we speak, we often use nonliteral utterances in which the meaning intended is different from the literal meaning. So, we must be able to differentiate what the speaker says from what he wants to say, using contextual information to understand the speaker’s intention and to make assumptions, predictions and inferences.The aim of this study is to determine whether there exists a hierarchy of complexity between various nonliteral speech acts. In other words, does an indirect request, for instance, require more processing to be understood than an ironic statement ? Some evidence was found for the existence of a hierarchy of complexity. Results emphasizes the particular role of “conventionality” and confirm the idea that conversational rules are very strongly dependent upon context.