while flying in the swan's plumage she had learnt the bird language; she had often conversed with the stork and the swallow, and she knew that the nightingale would understand. so she begged the nightingale to fly to the beechwood, on the peninsula of jutland, where a mound of stone and twigs had been raised to form the grave, and she begged the nightingale to persuade all the other little birds to build their nests round the place, so that evermore should resound over that grave music and song.

Make this proper case.
While flying in the swan's plumage she had learnt the bird language; she had often conversed with the stork and the swallow, and she knew that the nightingale would understand. So she begged the nightingale to fly to the beechwood, on the peninsula of Jutland, where a mound of stone and twigs had been raised to form the grave, and she begged the nightingale to persuade all the other little birds to build their nests round the place, so that evermore should resound over that grave music and song.