"Macbeth"'s linear structure means that when Duncan arrives at Inverness Castle, the audience is aware of the plot to kill him while he remains unaware.
STRUCTURE, FORM AND LANGUAGE
Macbeth: AS & A2
Macbeth's tragic flaw or hamartia is his ambition and greed for power. These cause his downfall.
Sickness symbolises the disorder in nature caused by Lady Macbeth and Macbeth's actions. Mental illness and Scotland's 'sickly weal' (V.2.27) are the outcomes of their evil.
In "Macbeth", the Witches symbolise evil, and references to darkness and blood help to convey this; conversely the imagery of light represents purity and salvation.
Duncan and his son represent the Divine Right of Kings. When order is restored at the end of the play the word 'grace' is repeated making this clear.