If a clause has an inflectional or syntactic position, one asks whether another clause is intended to participate in that position. When both clauses stand independently and the second is not to inherit the first judgment, grammar alone does not settle the issue: the degree of connection or disjunction must be examined.
Adding wāw can suggest a grammatical linkage, or lead a listener to extend the first clause’s assertion to the second. The grammatical status of a clause and its intended semantic relationship should therefore be distinguished.