Answer:
1. Because it shows that Beowulf is not perfect, then there is a reason to doubt his ability to beat Grendel.
2. The swimming match makes people doubt that Beowulf will be able to defeat Grendel, since she failed to win a foolish competition.
3. We are learning that Beowulf was indeed a hero, but he had certain limitations, which allows us to also see him as a human being.
Explanation:
Beowulf and Brecca had a silly swimming competition, just to show who was the fastest and best swimmer. Beowulf lost the competition and arrived after Brecca.
This defeat left many people unsure of Beowulf's ability to defeat Grendel. That's because Grendel was a powerful monster, the battle with him would be something serious and impossible to be won by a man who failed to win a swimming competition that had no significance.
This defeat of Beowulf teaches us that despite all the heroism and strength that he possesses, he remains a human being and is liable to fail like anyone else.
