Gertrude often anticipates, or correctly identifies, key moments, themes, or implications within the play as a whole.
Her clipped instruction to Polonius to speak ‘[m]ore matter with less art’ (2.2.96) identifies Polonius as a pretentious, rambling old fool while at the same time asserting her authority and intelligence – all of which is accomplished in a poetic heartbeat.
Her close relationships to the central male characters mean that she is a key figure within the narrative.
King Hamlet’s death and Gertrude’s wedding to Claudius happen immediately prior to the opening of the play.
The Ghost also speaks of Gertrude’s sexuality when he bitterly laments: The Ghost cites Gertrude’s voracious lust as the cause of her swift marriage to his brother (the ‘garbage’ in this metaphor).
Gertrude’s sexual relationship with Claudius defines her character for both Hamlets, and taints the audience’s perception of her as an intemperately lustful and self-indulgent individual.
She wilfully disobeys Claudius by drinking the poisoned wine. This, then, gives Hamlet the clarity of purpose, and the means and motive for revenge, which he has soliloquised over and struggled with throughout the play.
As the scholar Marguerite Tassi says of Gertrude, ‘[i]n fulfilling her tragic role, the end crowns all; in the final moments of her life, she performs an extraordinary act that gives Hamlet motive and cue for killing the King’., directed by Gregory Doran with David Tennant as Hamlet, portrayed Gertrude (played by Penny Downie) as overtly sexual.
Unlike her male counterparts, Gertrude does not have any soliloquiess and is therefore denied the opportunity to present her inner thoughts and feelings to the audience.
For these reasons, the true nature of her character and motivation is ambiguous.