Passive Voice
Use the passive when: the doer is unknown ("My bike was stolen"), the doer is obvious or unimportant ("The suspect was arrested"), you want to focus on the action rather than who did it (scientific writing: "The solution was heated to 80°C"), or to avoid assigning blame ("Mistakes were made"). Overusing the passive in everyday conversation sounds unnatural.
Use the passive when: the doer is unknown ("My bike was stolen"), the doer is obvious or unimportant ("The suspect was arrested"), you want to focus on the action rather than who did it (scientific writing: "The solution was heated to 80°C"), or to avoid assigning blame ("Mistakes were made"). Overusing the passive in everyday conversation sounds unnatural.
Practice
Which sentence most appropriately uses the passive?
In the experiment, the cellsat 37°C for 48 hours.
Transform to passive: put in the correct order: