Could you please tell me how you find these sentences? Books written by Indian writers often have such constructions in their exercises.

  1. Write these sentences in passive voice.
  2. Change these active sentences into passive.
  3. Convert these active sentences into passive.
  4. Turn these sentences into passive.
  5. Change from active voice to passive voice.




They all sound OK to me except 4. It feels like it needs an ending that isn't there, for example, "Turn these sentences into passive ones."