To change "I must go down to the seas again" into a negative sentence, you can say: "I must not go down to the seas again."
To change "I must go down to the lonely sea" into a complex sentence, you can say: "I must go down to the lonely sea because it calls to me."
To change "All I ask is a tall ship and a star" into a simple sentence, you can form it as: "I ask for a tall ship and a star."
To change "I want the wheel's kick and the wind's song" into a negative sentence, you can use: "I do not want the wheel's kick and the wind's song."
To change "The call of the running tide is a wild call" into a complex sentence, you can say: "Because the running tide calls, its call is wild."
To change "A wild call and a clear call may not be denied" into passive voice, you can say: "A wild call and a clear call cannot be denied."
To change "The call of the running tide is a wild call" into an interrogative sentence, you can ask: "Is the call of the running tide a wild call?"
To change "That may not be denied" into an affirmative sentence, you can say: "That must be accepted."
To change "The white clouds are flying" into a complex sentence, you can say: "As the white clouds fly, they cover the sky."
(i) To change "I want the flung spray and the blown spume" into passive voice and a negative sentence, you can say: "The flung spray and the blown spume are not wanted by me."
To change "I must go down to the seas to the vagrant gypsy life" into a complex sentence, you can say: "I must go down to the seas so that I can live the vagrant gypsy life."
To change "The wind is like a whetted knife" into a complex sentence, you can say: "When the wind blows, it feels as sharp as a whetted knife."
(i) To change "I want quiet sleep and a sweet dream" into a negative and passive sentence, you can say: "Quiet sleep and a sweet dream are not wanted by me."