One of the most difficult things in expressing the topic-comment structure of sentences in different languages is to identify which forms of one language are functionally equivalent to some other forms of another language. In order to accomplish such a task of identification, a general theory of topic and comment is needed, however, it seems that no satisfactory one has been so far available.
A solution of this problem was proposed by František Daneš in 1964, called "a three-level-approach to syntax", but it was not generally accepted. Based on his "anthropocentric model of communication", the author proposes reasons why František Daneš's theory should be considered as valid .