Key quotes:

Act 1:
• "Unseamed him from the knave to the chaps" - Macbeth has just "unseamed" the traitorous Macdonwald. Foreshadows Macbeth's killing by Macduff, and the word "unseamed" can be used to show the stripping of the traiter's title, which also foreshadows Macbeth's downfall.
• "Why do you dress me in borrowed robes?" - Suggests the title of Thane of Cawdor is not rightly Macbeth's.
• "Unsex me here" - Lady Macbeth is asking to be "unsexed", getting rid of her femininity, which was seen by a Jacobean audience as being weak and fragile, which was the opposite of what Lady Macbeth wanted as she wanted to be powerful.
Act 2:
• "Is this a dagger I see before me /The handle toward me hand? / Come, let me clutch thee" - During his soliloquy, Macbeth decides he is going to go through with the murder of Duncan, and he envisions a dagger, which acts as a literal and metaphorical path towards his murder of Duncan. Macbeth also slips in and out of iambic pentameter here, showing his slowly diminishing level of sanity and how he is giving in to Lady Macbeth, painting him as feminine.
• "Infirm of purpose. Give me the daggers!" - Lady Macbeth ridicules Macbeth for returning with the daggers, having not left them in Duncan's chamber. She uses the imperative verb "give", demanding Macbeth give her the daggers, making her seem in control and here Lady Macbeth is fulfilling the masculine role, whereas Macbeth is being mocked. This is against typical relationships in the Jacobean era, where men were in charge.
• "Will all great Neptune’s ocean wash this blood clean form my hand?" - Macbeth's guilt is beginning to overcome him as he is questioning his actions. The blood on Macbeth's hands is used to symbolise his guilt from the sacrilegious act of regicide that he committed, and he says that no amount of water shall remove the guilt (blood) that he has.
Act 3:
• "Be innocent of the knowledge dearest chuck" - This is a key quote as it shows Macbeth's abrupt change in character as he suddenly reveals his independence. Not only is he independently murderous, but he is now distancing himself from the previously dominant Lady Macbeth, dismissing her as "dearest chuck".
• "Full of scorpions is my mind" - Here, Macbeth's paranoia and dark desires are introduced. Scorpions are often associated with evil, and the word "full" shows that Macbeth has no other thoughts than evil ones, cementing him as a villain.
Act 5:
• "Out, damned spot Out, I say!" - Lady Macbeth's insanity is portrayed by her repetition of the imperative verb "out", trying to rid herself of a metaphorical "spot", though her efforts are futile. She is also sleepwalking here.
• "All the perfumes of Arabia will not sweeten this little hand" - Lady Macbeth is saying here that even the sweetest scents from Arabia - the finest perfumes - will not cleanse her of her guilt. The adjective "little" shows Lady Macbeth describing herself as innocent and fragile, the connotations of a child. Here, she is trying to justify her actions and thus her demise. She is sleepwalking here as well.
• "Give me my armour" - The use of the imperative verb "give" shows Macbeth demanding for his armour, returning to his previous role from earlier in the play, a soldier. He is trying to return to his old self, regretting his decisions.
• "Life is a tale told by an idiot full of sound and fury signifying nothing" - With the suicide of his wife, his source of confidence and power, and the knowledge of a large army advancing towards him, Macbeth has resorted to a pessimistic outlook on life, suggesting he does not feel true guilt.
• "Dead butcher and fiend-like queen" - Macbeth is described as a "butcher", which connotates violence and brutality and possibly even the fact that he brutally "butchered" Scotland in his own quest for power. Lady Macbeth is described as fiend-like, linking her to the witches as she influenced Macbeth to break his loyalty and go against everything he previously believed.