1. A computer natural language translation system, comprising: means for inputting source language text; means for outputting target language text; transfer means for generating said target language text from said source language text using stored translation data generated from examples of source and corresponding target language texts, characterised in that said stored translation data comprises a plurality of translation units, each comprising: respective surface data representative of the order of occurrence of language units of said source and target languages; respective dependency data related to the semantic relationship between said language units of said source and target languages; and the dependency data of language units of said source language being aligned with corresponding dependency data of language units of said target language, and in that said transfer means is arranged to use said surface data of said source language in analysing said source language text, and said surface data of said target language in generating said target language text, and said dependency data in transforming the analysis of said source text into an analysis for said target language.