Anaphora and repetition are commonly used in Martin Luther King’s “I have a dream....” speech because repeating the words and phrases helps to emphasise the pattern and increase the rhetorical effect. “I have a dream...” is repeated in eight successive sentences, and is one of the most often cited examples of anaphora in modern speeches. Repetition is a good device to use to strengthen an important idea. He uses and repeats the words dream, because it is such a personal and deep commodity. The phrases he adds to the end of this representation are also very personal. This is so effectual because the target audience of this speech can see these visualizations become reality. Even now, over 30 years after his death, reading through the speech gives the reader a sense that things are not complete, and that King still has a dream.
If you count the frequency of words used in King’s “I Have a Dream”, very interesting patterns emerge. The most commonly used noun is freedom, which is used twenty times in the speech. This makes sense, since freedom is one of the primary themes of the speech.
A metaphor is a very effective way to illustrate an idea. King uses many metaphors, both large and small, to describe many different ideas. “In a sense we have come to our nation's capital to cash a check. When the architects of our republic wrote the magnificent words of the Constitution and the declaration of Independence, they were signing a promissory note to which every American was to fall heir. This note was a promise that all men would be guaranteed the inalienable rights of life, liberty, and the pursuit of happiness. It is obvious