Before accepting a converted sentence, check all 4 points.
1. Does a noun or detached pronoun now begin the sentence as mubtada?
2. Does the following past verb match it in person, number and gender?
3. Did the object and other complements keep their original roles?
4. If the original verb was passive, did it remain passive?
Examples: خَرَجُوا مِنَ الْمَسْجِدِ ← هُمْ خَرَجُوا مِنَ الْمَسْجِدِ; شَرِبْنَا الْمَاءَ ← نَحْنُ شَرِبْنَا الْمَاءَ.