How did Beowulf finally defeat Grendel's mother?

"Although his sword, Hrunting, loaned to him by Unferth, fails to penetrate the mother's hide, Beowulf discovers a giant magic sword in the cave and is able to kill the mother with it. The sword melts to its hilt after Beowulf uses it to decapitate the corpse of Grendel, which lies nearby."

Grendel's Mother - CliffsNotes

Explanation:

the present continuous is a verb tense which is mainly used to indicates that an action is in progress at the moment of speaking.  

it is formed using: person + verb to be (am/is/are) +verb + - ing form  

example: i am studying at this moment .

in addition, the present continuous is also used in order to express things that will or will not happen in the near future.

example: i am having dinner with some friends tonight.

the speaker sometimes   uses it   to express that an action is repeated and it causes irritation on the part of the speaker

example: my sister is constantly complaining about everything.

can you elaborate on what the question asks?