Many different scholars have studied the Speech Act Theory. They all contributed to the development of the theory. The most prominent among them is the American philosopher-linguist John Searle, who followed Austin’s line of research but refined his theory at the same time. He has made a thorough study of speech acts, focusing on the appropriate conditions for the implementation of the illocutionary acts (preparation condition, sincerity condition, propositional content condition, and basic condition) Searle (1979) classified illocutionary acts into five general types: representatives, directives, commissives, expressives and declarations.
Representatives means the speaker states or describes something to others, saying what the speaker believes to be true. For example, the sentence “The earth is globe not square.” is a classical example to elaborate representative illocutionnary acts.
Directives means the speaker tries to get the hearer to do something. For instance, a mother tells her child “Finished you homework if you want to play video games.” or “Open the window, please!” 美剧《欢乐一家亲》中的言语幽默分析(3):http://www.751com.cn/yingyu/lunwen_48073.html