В пособии рассматриваются основные моменты английской грамматики: части речи имя существительное, имя прилагательное и наречие; видо-временные формы глагола; модальные глаголы; неличные формы глагола

8. Passive Sentences with or without by:

A. In a passive sentence, when we want to say who or what did the action, we
use by:
We were stopped by the police.
The paper was all blown away by the wind.
In a passive sentence we mention the agent, the person or thing doing the
action, only if it is important. We do not mention the agent when:
1. the agent does not add any new information:
The money was stolen.
The men were arrested last night.
We do not need to say that the money was stolen by a thief or that the men
were arrested by the police.
2. the agent is not important:
Oil has been discovered in Bavaria.
Who discovered the oil is less important than the fact that it is there.
3. it is difficult to say who the agent is:
This kind of jacket is considered very smart.
A number of attempts have been made to find the Loch Ness monster.
B. We can give other details about the action. For example, when we want to say
when or where something happens, we can use in, to or at:
The telephone was invented in 1876.
The visitors will be driven to the airport.
The concerts are held at the university.


C. After some past participles which are used like adjectives (to describe a state
of mind, not an action), other prepositions are used instead of by to introduce
the agent. Compare:
She was frightened by a mouse that ran into the room.
I’ve always been terribly frightened of spiders.
D. With is used when we talk about an instrument which helps the agent to do
an action.
He was shot with a revolver.