The author of the article understands object clauses as a semantic type of sentences with a set of different ways of expressing semantics: polypredicative subordinate clauses, asyndetic clauses, monopredicative clauses, clauses with parenthesis. It is suggested that the set of constructions used in academic discourse depends on the genre of the academic text. The genres of article abstracts and thesis summaries as secondary texts (texts about texts) were chosen as a material for a comparative study.