Passive voice

1. Form:

We form the passive like this: to be + past
participle.

Present simple	Diamonds are found in South Africa.
Past simple	The goods were delivered yesterday.

2. Use:

We use the passive when it is not important who does
the action, or when we don't know who it is:

e.g. this castle was built in the 16th century (we don't know who built it).

We also use the passive because we have been talking
about something, and not the person who did it. We use 'by' to say who does/did
the action.

E.g. this film was made in 1956. It was directed
by Hitchcock.

3. Active and passive:

Passive verbs have the same tenses as active verbs
	Active	Passive
Present simple	She cleans the room every day.	The room is cleaned every day.
Past simple	He cleaned the room yesterday.	The room was cleaned yesterday.