Final answer:
Grendel in the epic poem 'Beowulf' can't be harmed by swords and weapons because he is under a divine curse that grants him immunity to ordinary physical damage. This requires Beowulf to defeat Grendel using his bare hands.
Step-by-step explanation:
The question, 'Why can't Grendel be injured by swords and weapons?' relates to the Old English epic poem Beowulf. In this literary work, Grendel is depicted as a monster cursed by God, and the text suggests that no earthly weapon can harm him because of this divine protection. Therefore, despite the efforts of the warriors to fight Grendel with conventional arms, their attempts are futile.
It is implied that Grendel's invulnerability is a result of enchantment or a spell that makes him immune to ordinary physical damage. This characteristic of Grendel serves to heighten the drama of the poem, as it requires the hero, Beowulf, to face him with strength and courage alone, without the aid of weapons, ultimately defeating the monster through hand-to-hand combat.