Passive voice and active voice

其實冇話幾時用既........
考試時佢可能會叫你將acrive voice 轉做passive voice

Active voice: John kill Mary.
Passive voice: Mary is killed by John.

Active voice 係我地普通常用既句子, passive voice 就係將句子既主語轉去後面(John), 再係前面加 by, verb 要轉做p.p..

eg: Someone broke Tommy's house.
passive voice: Tommy's house was broken (by someone).

係呢到,verb to be 要轉做was..............someone可以省略因為唔知個個人既真正身份