This paper aims at investigating the use of local prepositions by native speakers of the Portuguese language in the process of formal acquisition of the German language as a second language. In order to perform this study, the selection and analysis of German and Portuguese language grammars, as well as educational books used in the process of German language teaching-learning, were carried out. In addition to the previously mentioned bibliographic material, this research also included a corpus of data in written language, extracted from exercises related to the use of local prepositions in German, which were applied to students of Secondary School. Thus, this paper was organized as follows: the Introduction outlines the theme and explains the motivation for this study; Chapter 2 refers to a number of theories related to the bilingualism phenomenon; Chapter 3 investigates the selected grammars´ approach to the categories of prepositions; Chapter 4 details, amongst the adopted procedures, the methodology, the profile of the participants and the conditions of acquisition of the German language; Chapter 5 examines the educational material used by the students participating of the sample; Chapter 6 analyzes the data obtained; and finally, Chapter 7 presents the conclusions achieved with this study.