The Grammaring Guide to English Grammar with Exercises

The agent with the passive voice

The agent is the person or thing that performs the action and is the subject of the active sentence. In most passive sentences, the agent is not mentioned. If it is mentioned, however, it is usually preceded by the preposition by:

The pigeons were dispersed

by a tourist walking past

.

(

A tourist walking past

dispersed the pigeons.)

He was hit

by a falling branch

while walking in the woods.

(

A falling branch

hit him while he was walking in the woods.)

The instrument is an object that is not the doer of the action but something that the doer uses in performing the action. If it is mentioned in the passive sentence, it is preceded by the preposition with:

The crowds were dispersed

with tear gas

.

(The police dispersed the crowds

with tear gas

.)

He was hit

with a branch

while walking in the woods.

(Someone hit him

with a branch

while he was walking in the woods.)

(In the two passive sentences above, the agent is not mentioned. In the first sentence the identity of the agent is obvious, while in the second one it is unknown.)

With is also often used with the verbs fill, crowd, cram and pack:

The bottle

was filled with

whiskey.

The hall

was crowded with

people standing and lying on the floor.

Our room

is crammed with

furniture.

The preposition in is often used with cover:

When I looked out the window in the morning, I saw that the streets

were covered in snow

.