The aim of the study is to identify and interpret the exact aspects of Greek interlanguage modification which present deviations from native usage. As such, it is an investigation of Greek ESL university students' request modification and a comparison to British English native speakers. More specifically, it concentrates on the mitigating function of lexical/phrasal modifiers and of external supportive moves in socially similar situations and examines whether the two language/cultural groups use combinations of internal/external modifiers in the same way and to the same extent. The study aims to make a contribution to the field of interlanguage pragmatics by identifying pragmatic requestive features which characterise second language speech acts and can therefore benefit from pedagogical attention. This study found the learners to display an underuse of lexical/phrasal downgraders (internal modification) as compared to native speakers, and to generally use more supportive moves (external modification). The learners used more "combinations" of supportive moves than native speakers did but fewer "combinations" of internal modification devices, thus exhibiting a rather restricted pragmatic repertoire in their production. These results are compatible with previous interlanguage studies.