Background. How is the obligative (cf. Denning 1987: 45-55) expressed in the genetically unrelated languages of German and Turkish? Which paradigm of deontic modality is rendered for German, which one is rendered for Turkish, and what kinds of relations exist? Materials and Methods. The masks were developed based on the work of Buscha et al. (1971: 38,40) and Ersen-Rasch (2001: 173-174). The first mask (the first questionnaire) contains an authoritative relationship (a birthday party ordered by a mother); the second questionnaire contains 15 questions based on 3 masks derived from Ersen-Raschs (2001) model: “external compulsion,” “internal compulsion,” and “general necessity.” The relationship of authority is balanced here. The data were collected using audio recordings of the utterances of 9 informants from Austria and Turkey. Analysis. The obligative forms gathered in the data corpus were first analyzed within each individual language and then across the languages according to informants, forms and form groups and quantity. Results. In Turkish, “internal compulsion” is not represented as a modal force. However, “internal obligation” does occur as a modal force. Forms of “sollen” in the indicative present and subjunctive preterit differ with regard to the feature of authority. If there is a relationship of authority between the speaker and the person being addressed, indicative present is used. However, if the relationship of authority is balanced, the subjunctive preterit is selected. In Turkish, both forms correspond to the necessitative and denote a weak obligation.Forms of “müssen” in the indicative present, which represent the stronger obligative in German, correspond to three basic forms in Turkish: not only the strong obligative form “zorunda,” which conveys compulsion, but also the other medium-strength obligative forms of “gerekmek” in the present and “lazım,” which express necessity.