Epanalepsis repeats the beginning word of a clause or sentence at the end. The beginning and the end are the two positions of strongest emphasis in a sentence, so by having the same word in both places, you call special attention to it:

• Water alone dug this giant canyon; yes, just plain water.
• To report that your committee is still investigating the matter is to tell me that you have nothing to report.

Many writers use epanalepsis in a kind of "yes, but" construction to cite common ground or admit a truth and then to show how that truth relates to a more important context:

• Our eyes saw it, but we could not believe our eyes.
• The theory sounds all wrong; but if the machine works, we cannot worry about theory.
• In the world you have tribulation, but take courage; I have overcome the world. --John 16:33 (NASB)