The French language was marked by significant shifts during the sixteenth century that would settle into more standardized usage thereafter. The purpose of this volume, a comparative grammar, is to discern transitions in modal syntax and to formulate the rules that governed it during that time. Major sections address rules regarding usage after declarative expressions; after expressions of emotion; after expressions of volition or necessity; in adverbial clauses of purpose; in consecutive clauses; in comparative clauses; in temporal adverbial clauses; in causative adverbial clauses; in adverbial clauses of concession; and a general summary of subjunctive usage.