To make a verb passive, we use the verb be conjugated in the same tense used in the active voice‏‎ and change the main verb into the past participle.

These are the main patterns used:

Simple Tenses

active

Eric kisses Amanda.

passive

Amanda is kissed by Eric.

active

Eric kissed Amanda.

passive

Amanda was kissed by Eric.

Continuous Tenses‏‎

active

Eric is kissing Amanda.

passive

Amanda is being kissed by Eric.

active

Eric was kissing Amanda.

passive

Amanda was being kissed by Eric.

Perfect Tenses‏‎

active

Eric has kissed Amanda.

passive

Amanda has been kissed by Eric.

active

Eric had kissed Amanda.

passive

Amanda had been kissed by Eric.

When we use auxiliary verbs‏‎, we add them to the front of the structures above:

Amanda could be kissed by Eric.
Amanda is going to be kissed by Eric.

Amanda might be being kissed by Eric.

Amanda will have been kissed by Eric.
Amanda ought to have been kissed by Eric.

To make the passive Infinitives follow these patterns:

PRESENT

active

Someone ought to help him.

passive

He ought to be helped.

PAST

active

Someone ought to have helped him.

passive

He ought to have been helped.

Sometimes you can use get instead of be to make the sentence a little more informal.

The phone box was vandalized last night.
The phone box got vandalized last night.

This is generally used in speech rather than writing.

N.B. Not all active verbs can be turned into passive. Verbs which cannot be followed by objects cannot be used in the passive voice‎. These types of verbs are called intransitive verbs.

Some intransitive verbs are: appear, arrive, come, cry, die, go, happen, occur, rain, sleep, stay, walk. These verbs cannot be used in the passive voice‏‎.