Looking up the pronunciation of a French word

Consider a module that takes two arrays of integers, and creates and returns a new array of integers whose elements are the sums of the respective elements of the input arrays.

How might this module fail? If this module were responsible for recovering from these failures, how might it do so?

Provide an interface specification for a module that serves as an English–French dictionary. The module should provide facilities for adding new words to the dictionary, looking up the pronunciation of a French word, and returning the French word that corresponds to an input English word.