The work presented in this thesis lies in the general field of the natural language processing and is concerned with machine translation specifically Machine translation (MT) is considered to be one of the important application areas where the analysis and generation of natural langauge sentences are Involved. The work is an attempt to design a machine translation system of interrogative sentences from English to Arabic langauges in a restricted domain (school domain), called MATSIS. The acronym MATSIS stands for MAchinc Translation System of Interrogative Sentences MATSIS system uses the transfer strategy coupled with the interactive and post editing approaches. It is based on the syntactical and semantical analysis of sentences where solutions of some dictionary problems ( regularties and different shades of meaning of words ) are tackled MATSIS in its present form is limited to some structures of interrogative sentences but it is aimed to be flexible in the sense that more types may be added by expanding the acceptable grammar rules, grammatical category types, and possibly more languages may he included All the work in this thesis is carried out on an IBM compatible PC, using AIN Arabic software and turbo PROLOG (ver. 20) langauge.