Ответ:

  1. Do you wish you were swimming in the clear blue sea?
  2. Do you wish you could climb the world’s highest mountain?
  3. Can you imagine standing in front of the Pyramids?
  4. Do you dream of staying in a four-star hotel?

После were используется форма на -ing; после модального глагола could — начальная форма глагола; после imagine и dream of употребляется форма на -ing.