Hamm says Clov loved him once, and Clov emphasizes "Once!" Nagg says the sand in his ashbin was "once" sawdust, and Nell also emphasizes "Once!" What are the possible reasons behind Beckett's emphasis on this word?

The word "once" is often used ambiguously; does it mean "one time," or "formerly" (i.e., was the sawdust used one time, or was it previously used all the time)? In other words, is "once" an indicator of a single instance or of an entire collection of instances? The question is similar to Clov's grain/heap question; is a pile of grains simply an accumulation of distinct grains, or is it a heap? This tension seems less important for Nagg and Nell's example (although sand and sawdust, of course, are also composed of grains). It is more crucial to Hamm and Clov's relationship. First, can love truly be so fleeting as to exist at one point only? Second, once love has existed, how can it be extinguished? In Endgame's miserable landscape, it's easy to see how hatred can overtake love, but it is not so clear that Clov has truly stopped loving Hamm. He complains incessantly about servicing Hamm's every whim and even goes so far as to hit him with the toy dog, but there must be something beyond obligation, fear of solitude, and a cyclical universe that prohibits departures and arrivals keeps Clov next to Hamm. Near the end of the play, Hamm suggests it is compassion. While Clov doesn't openly agree with this, he doesn't reject it either. Perhaps, then, the "once" has overcome its state of singularity ("one time") and past tense ("formerly") and flows through time after all.

Why does Nell die in a play where everything is cyclical? Shouldn't she live forever, just like the others?

It is unclear if Nell truly does die—Beckett was opaque about this in conversation as well, even with the actors he was directing. Assuming she has died, perhaps it is only temporary, and she will be resurrected the next day. In the cyclical world the characters inhabit, this is not an implausible idea—maybe her death is a daily routine. A more likely reason for her death is that Nell is the one character who understands her limitations—she knows that she and Nagg can't kiss, and calls the routines they go through a "farce." Her reward, then, is death, since she is the only one who accepts it in her life, while the others, Hamm especially, "hesitate" to "finish" life though they despise it. Her death also exposes the callous attitudes to death of the others. Nagg eats his biscuit and seems unfazed, and Hamm is even less perturbed. Ironically, while he shows little emotion at his mother's death, he remarks that Nagg seems to have quickly forgotten Nell, though Nagg was crying at one point. Once a person is out of their lives, or knocked out of their circular loop, it is as if she has never existed. The characters' memories extend back to childhood, unlike in Waiting for Godot, where they have trouble remembering yesterday's events. Even so, they seem to displace that which has preceded them because if it does not affect them currently, it never will.

Discuss the role of Hamm's toy dog.

Most obviously, the toy dog shows that Hamm can show affection only to that which is inanimate. Even in a ravaged world with little remaining life, he is afraid to devote himself openly to other humans. Later, however, he rejects the toy dog, throwing it away with his whistle at the end of the play. The whistle, of course, was his tie to Clov, the real object of Hamm's affections—though he was loath to admit it. The dog also plays a role in Clov's life. Though he doesn't admit it, Clov seems jealous of the attention Hamm lavishes on the dog. At first, Clov holds up the dog and pretends it is standing up for Hamm, letting the old man believe it is a functional pet. But later he waits before retrieving the dog for Hamm, who believes it has gone away. Finally, he hits Hamm with the dog after being sent on one errand too many. Hamm bitterly says Clov should not hit him with the dog; he'd rather Clov used the gaff or an axe. His point is clear: Clov has used the one object that gives Hamm some human joy against him.