The article refers to the functional sentence perspective in the popular-science texts from the Scientific American. The communicative functions of various adjuncts in the initial, final, and intermediate positions in declarative sentences have been analyzed. The function of theme does not appear to be typical of the adverbial modifiers of place, time, and manner. It is more logical to speak about the function of antetheme (anticipatory theme) with reference to both detached and non-detached adverbial modifiers in the initial position in the sentence. By their semantics, these adverbials are presuppositionally connected with some known facts in human minds, but in the sentence structure, they are followed by the actual communicative core of utterance in the form of subject and predicate. Adjuncts in the final position regularly perform the function of rheme. Such sentences make up the bulk of our corpus.
Keywords: functional sentence perspective, theme, antetheme, rheme, topic, focus, adverbials, communicative dynamism, popular-science text, discourse, proposition, presupposition.