In English, Passive Voice is used when we want to emphasize the action rather than the subject of that action. Or we can also use it when the subject is unknown. So, depending in what we want to highlight we can say the same idea in two different ways.

Eg:

Active Voice: " We paint the house every summer." ( The most important part of the speech is WE, the one that is doing the action)

Passive Voice: "The house is painted evey summer." ( Here the aspect that is emphasized is the action IS PAINTED)

*If you want more info and practice click here

*If you are going further, and you need to know about impersonal passive or passive with two objects click here.

As you can see there are some changes in the order of the different elements in the sentence as well as in the verb.

Here you have a chart with the most important changes in the verb when you are turning active voice into passsive.