In the fight with grendel, beowulf's followers are unable to harm grendel because:

type of error:

the error in the sentence is a "dangling modifier". a dangling modifier is a phrase, word or clause that "dangles" because there is not target to modify. in this case, "after mopping the floor" is the dangling modifier since it has no word to modify. the noun "house" cannot mop the floor; therefore there is a mistake in the writing of the sentence.

i believe that dan is so anxious because he dose not know what awaits him when he gets there. but i dont know to be honest