In some translations, the source text influences the syntactic structures or the lexis of the target text (shining-through), while other translations contain fewer traces of language transfer than original texts in the target language (normalization). On the lexical level, this can be seen in the number of cognates. There is no definite answer to the question of how these phenomena can be linked to mental processes yet. However, psycholinguistic literature shows that the shining-through effect can be explained by the structure of the mental lexicon as well as the mechanisms for accessing words: the cognate-facilitation-effect. The aim of this study is to provide an explanation for normalization. The hypothesis was that verbal self-monitoring, after the first activation of words but before articulation, filters out cognates. For this purpose, written and oral translations were compared. Written translations, which are monitored more strongly, contained fewer cognates than oral translations. Accordingly, the interpretation of this study was that self-monitoring filters out cognates before the translator starts writing and that it is therefore an important factor for normalization.