Derrida speaks of "iterability" throughout his works. We are accustomed to hearing people say, "could you reiterate that?" -- ordinarily, in other words, one would expect to see the word "reiterate" rather than merely "iterate." What Derrida stresses by using the word iterate is that any word which can be said by one human being to another must, if it is at all comprehensible, be repeatable. Every iteration is, therefore, a reiteration: words appear in dictionaries before you use them; you might imagine yourself, in speaking, as quoting the dictionary.