Change the voice-
1) Write neatly.
2) Alas! he is dead.
3) Don't open the window.
4) Who taught you Spanish?

Dear Student,
Given below is the answer to your question.

Please note that there is no object in the first two sentences and therefore it cannot be changed.
3. The window should not be opened.
4. By whom was Spanish  taught?

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Thank you.