According to traditional grammar conjunctions are words connecting clauses (or words / word combinations). Still many conjunctions can also connect sentences and longer fragments of texts, being in fact connectors (these are «soft» conjunctions), while some conjunctions are able to connect only clauses (these are «hard» conjunctions). Many Russian conjunctions, both coordinating and subordinating, are soft, but there are also hard coordinating and subordinating conjunctions. Hard conjunctions are easily described in the frameworks of valency theory as predicates with (at least) two semantic and syntactic actants. Soft conjunctions and connectors also have two semantic actants. But at least one of these actants cannot be revealed in a text by an algorithm. It is argued that some refi nements of valency theory are necessary for representing syntactic properties of connectors and soft conjunctions.