It had been so with us, had we been there:  

His liberty is full of threats to all;

To you yourself, to us, to every one.

Alas, how shall this bloody deed be answer'd?"

We go to gain a little patch of ground

That hath in it no profit but the name.

To pay five ducats, five, I would not farm it; 

Nor will it yield to Norway or the Pole

A ranker rate, should it be sold in fee."

Cries cuckold to my father, brands the harlot

Even here, between the chaste unsmirched brow

Of my true mother."

A sister driven into desperate terms, 

Whose worth, if praises may go back again,

Stood challenger on mount of all the age

For her perfections: but my revenge will come."

It had been so with us, had we been there:  

His liberty is full of threats to all;

To you yourself, to us, to every one.

Alas, how shall this bloody deed be answer'd?"

Said by King Claudius, this quote furthers the plot by officially declaring Hamlet's madness.  Because of the supposed danger he poses to society, he opens the perfect window of opportunity for Claudius to send him away to England, only to later be assassinated.  This quote expresses the motif of deceit lead by Claudius throughout the play.  Anything he does -- from marrying Gertrude to killing the King -- is to seize the throne.  This includes disposing of the threat Hamlet himself poses.

Cries cuckold to my father, brands the harlot

Even here, between the chaste unsmirched brow

Of my true mother."

Spoken by Laertes in context of his father's death, this quote works to display him as Hamlet's foil.  While Hamlet sat around and played madness after the King's death, Laertes rushed home to seek vengeance upon whomever was responsible for Polonius's death.  It furthers the plot by expressing Laertes's grief and eventual build up to bloodlust. 

This quote is significant because it encompasses the motive of both Hamlet and Claudius. Both characters seek a response to the rash actions of the other. Claudius doesn't know what to do with Hamlet and Hamlet doesn't know if he can get revenge against Claudius. Both characters, also, question their own actions and their "heavy deeds". Claudius occasionally regrets killing Old Hamlet. Hamlet doesn't understand why he can't kill. Furthering the plot, this quote foretells and foreshadows that both Claudius and Hamlets actions will lead to doom for all. The theme that can be seen within this quote would be free will and the consequences that come with it. This can specifically be seen with the line "liberty is full of threats to all." It shows that any one can do as they please - including kill. The big picture seen with this quote is the irony. Claudius is judging Hamlet for killing, calling him rash, mad, and a threat. In truth, this describes him more than Hamlet. His "bloody deed" has been answered with more blood. His liberty has threatened Hamlet who completes the circle by threatening Claudius in return. Claudius is questioning Hamlet when, in truth, he should be questioning himself.

This quote is significant because it is both a comparison and a contrast to Hamlet's situation. In contrast, Fortinbras has suffered the same loss as Hamlet - the loss of his father.  However, he is getting his revenge. He won't let fear conquer him and his pursuit. Hamlet is a coward. He even admits it. He is too afraid to get justice for his fathers death like Fortinbras. In comparison, both Hamlet and Fortinbras' efforts are fruitless. As shown by the valueless land, nothing good comes out of revenge. All efforts for revenge are wasteful. This also furthers the plot. It leads us into understanding the death in Act V as being just as wasteful. This quote also makes use of the land motif used throughout  the novel. Similarly to the references of Denmark being a rank garden, Fortinbras also seeks to make use of useless land. However, its inability to be farmed - its inability to produce life - suggests that only death will come.