The use of German articles is a source of many linguistic mistakes for Polish students at any level of proficiency. The analysis presented in this paper focuses mainly on those incorrect uses of the definite, indefinite and zero article which distort the meaning of the message and may lead to disturbance in the process of linguistic communication. It is the main point of the paper, therefore, to look at the article and the category of in/definiteness it expresses from the perspective of cognitive linguistics. Based on the principles of cognitive linguistics as formulated by Langacker (1995, 2005), the author defines the category of in/definiteness in term of Langacker's viewing metaphor, and attempts to describe and explain the functioning of the less frequent uses of articles in German.