Passive : be + past participle

Present
Positive		Negative		Questions
Rissotto is made with rice.		It isn't made with rice.		Is it made with rice?
These offices are cleaned every morning.		They aren't cleaned on Sundays.		Are they cleaned on Saturdays?
Past
Positive		Negative		Questions
Guernica was painted by Picasso.		It wans't painted by Miró.		When was it painted?
The pyramids were built by the Egyptians.		They weren't built by the Romans.		Why were they built?

You can often say things in two ways, in the active or in the passive.
Picasso painted Guernica. (active) / Guernica was pianted by Picasso. (passive)

In the active sentence, the focus is more on the person.
In the passive sentence, the focus is more on the painting.

You can also use the passive when it's not know or not important who does or did the action. My car was stolen last week. ( I don't know who stole it)

Present passive - am/is/are + the past participle.
Past passive - was/were + the past participle.

Use by to say who did the action.