This present paper is devoted to the analysis of modal auxiliaries in Martin Luther King’s speech (I have a dream). This speech was delivered at the march on Washington for jobs and freedom. In this speech King has used modality through modal auxiliaries and there is a wide range of meanings that these words are used to express. The phrase “modal auxiliary” shows that there are two linguistic forms which are under question: the syntactic notion of “auxiliary” and the semantic notion of “modality” Thus, not all modal auxiliaries have been analyzed in this present study; but some of them such as Will, Shall, Must and Can in their predicative and inter-subjective relationships.