We can use this special pattern with verbs of reporting when we do not need to know who is doing the reporting. Sentences of the type People consider/know/think etc. that he is... have two possible passive forms:
It is considered/known/thought etc. that he is...
He is considered/known/thought etc. to be...
The infinitive construction is the more exact of the two. It is chiefly used with to be though other infinitives can sometimes be used:
He is thought to have information which will be useful to the police.
Perfect infinitive is used when the thought concerns a previous action.
People believe that he was =
It was believed that he was or He was believed to be...
People know that he was =
It is known that he was or He is known to have been...
This construction can be used with the perfect infinitive of any verb.
We use this construction after acknowledge, assume, believe, claim, consider, estimate, expect, feel, find, intend, know, presume, report, say, think, understand. With the other verbs in this group (agree, announce, arrange, decide, fear, hope, regret) the that- structure is more common.
B. Supposed to
Sometimes (be) supposed to means ‘said to’:
Let’s go and see that film. It’s supposed to be very good.
(= It is said to be very good; people say that it’s very good.)
He is supposed to have stolen $60. (= He is said to have stolen $60.)
But usually supposed to has an idea of duty and is not therefore the normal equivalent of suppose in the active:
You are supposed to know how to drive = It’s your duty to know.
You can use suppose to to say what is arranged or planned (and this is often different from what really happens).
The train was supposed to arrive at 11.30 but it was 40 minutes late.
You were supposed to clean the windows. Why didn’t you do it?
We use not supposed to to say what is not allowed or not advisable:
You’re not supposed to park here. (=You are not allowed to park here.)
Mr Collins is much better after his illness but he’s still not supposed to do any heavy work.
supposein the passive can be followed by the present or perfect infinitive of any verb. It may have an idea of duty but very often does not:
You are supposed to have finished = You should have finished
but He is supposed to have escaped = People suppose that he escaped
C. have something done
1. This construction can be used to express more neatly sentences of the type ‘I employed someone to do something for me’; i.e. instead of saying I employed someone to clean my car we can say I had my car cleaned, and instead of I got a man to repair my roof, we can say I had my roof repaired.
The word order is important: the past participle (cleaned/repaired etc.) comes after the object (the car/the roof).
have + object + past participle
Jill had the roof repaired yesterday.
Where did you have your hair done?
We are having the house painted at the moment.
Tom has just had a telephone installed in his flat.
How often do you have your car serviced?
Why don’t you have that coat cleaned?
I want to have my photograph taken.
‘Get something done’ is possible instead of have something done but is more colloquial.
We must get another key made.
2. Have something done sometimes has a different meaning of have something happen(usually by accident or misfortune).
We had our passports stolen.
He had two of his teeth knocked out in the fight.
You can see that if in A above the subject is the person who orders the thing to be done, here the subject is the person who suffers as a result of the action. The subject could be a thing:
The houses had their roofs blown off by the storm.