her sister preferred to stay in copenhagen, whereas the other swam up the vistula river and ended up in warsaw. being a dane i find this very unlikely, as any dane knows that the danish mermaid's sisters all live in the sound between denmark and sweden.

Write the above sentence using proper case.
Her sister preferred to stay in Copenhagen, whereas the other swam up the Vistula river and ended up in Warsaw. Being a Dane I find this very unlikely, as any Dane knows that the Danish Mermaid's sisters all live in the Sound between Denmark and Sweden.