1. A computer-assisted language generation system comprising: sentence retrieval functionality, operative on the basis of an input text containing words, to retrieve from an internet corpus a plurality of sentences containing words which correspond to said words in the input text; and sentence generation functionality operative using said plurality of sentences to generate at least one correct sentence giving expression to the input text, said sentence generation functionality comprising: sentence simplification functionality operative to simplify said sentences retrieved from said internet corpus; simplified sentence grouping functionality for grouping similar simplified sentences provided by said sentence simplification functionality; simplified sentence group ranking functionality for ranking groups of said similar simplified sentences; and sentence selection functionality operative to select at least one of said similar simplified sentences as said at least one correct sentence based on said ranking; said simplified sentence group ranking functionality operates using an extent to which the group includes words which do not correspond to the words in an independent phrase and their alternatives.