This study investigated the performance of native and non native speakers of Modern Greek language on morphology and syntax tasks. Non-native speakers of Greek whose native language was English, which is a language with strict word order and simple morphology, made more errors and answered more slowly than native speakers on morphology but not syntax tasks. It seems that Greek free word order is not a problem for non-native speakers who come from a country where the language spoken has strict word order. However, complex morphology of Modern Greek, such as plural markers, causes difficulties to non-native speakers whose native language has simple morphology.