The passive voice is formed with the verb to be + the past participle of the verb:

Many new roads were built during the last years in my hometown.

The verb to be should always be changed into the correct tense to make passive voice. Let's consider the verb to eat, look how it changes in passive voice:

• The soup is eaten every day (present simple)
• The soup is being eaten right now (present continuous)
• The soup has been eaten this week (present perfect)
• The soup was eaten yesterday (past simple)
• The soup was being eaten for 1 hour yesterday (past continuous)
• He told me the soup had been eaten the day before (past perfect)

To make the negative, we need to put not between the verb to be and the past participle: I was taught not to litter.

After modal verbs we use the passive infinitive without to: Do not worry, it can be done.

With active verbs we usually follow this pattern: subject + verb + object (Parents told children to stop playing). But when we use passive, we want to put the object of the verb first: The children were told to stop playing. (object + verb).

We use the passive voice:

1. When we want to focus on the object of the sentence:

My car was cleaned today. (The focus is on the car in this situation)

2. When we know from the context who carried out the action:

A law was proposed to protect the rights of the people. (We know that the government proposed it)

3. When it is not important who carried out the action:

Fresh food is brought to the supermarkets everyday. (We don't care who brings it)

Note:

We can include the subject by adding "by + the person/group of people" when we need to do so. For example: We were told to do so by our parents. In most cases, however, it is omitted.