Passive construction

[svartnik]

Close but no cigar.

[greegorush]

Pinch of sugar?

It should have the opposite meaning of the expression which has been meant by Svartnik.

[Daruma]

Svartnik,

It is reported that two people were injured in the explosion.
It would be possible to say "have been" in place of "were," but doesn't it change the meaning of the sentence?

A friend of mine has been arrested. It is alleged that he hit a policeman.
It would be possible to say "has hit" in place of "hit," but doesn't it change the meaning of the sentence?

[svartnik]

The meaning is changes in the first sentence with the shift of tenses, in my opinion.

The present perfect is more proximate in time to me. Futhermore, the simple past involves the possibility of their recoverance from the injury they sustained.

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A friend of mine has been arrested. It is alleged that he hit a policeman

Same here.

[bhaisahab]

The meaning is changes in the first sentence with the shift of tenses, in my opinion.

The present perfect is more proximate in time to me. Futhermore, the simple past involves the possibility of their recoverance from the injury they sustained.

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To me the use of the present perfect doesn't preclude the possibility of recovery. Why do you think it does?

[svartnik]

I expressed myself ineffectively.

It is reported that two people were injured in the explosion. -- not sure they are still injured

It is reported that two people have been injured in the explosion. -- still injured

Well, it is not a good pair of sentences to illustrate the difference between the two uses of tenses, but most of the time this distinction holds true. Reported sounds very immediate to the present time and we can not heal in one stroke.

[orangutan]

Just to step back for a moment from the question of tense...

1. It is said (alleged, believed, supposed etc.) that
2. He is said to

I've got a few questions about the structures above:

1. Could I leave out that in the 1 case?

Yes, though it strikes me as slightly less usual in this case.

2. It is not clear to me what form of a verb we should use:

It is reported that two people were injured in the explosion (is it possible to use have been injured here?)

A friend of mine has been arrested. It is alleged that he hit a policeman (could I say has hit?)

See above posts.

3. Am I right that It is supposed to could be used as alternative to the other possible verbs without changing the meaning?
For an example: It is suppose (instead of reported) that two people were injured; it is supposed (instead of alleged) that he hit a policeman.

Thanks in advance!

"It is supposed to" seems to me to be conflating the two constructions in your original question. We can say "it is supposed that [X did Y]" or "X is supposed to [have done Y]". (Of course X can also be "it", but I don't think that is what you meant.)

It seems to me that these two are not quite synonymous, with each other or with your first examples. "He is supposed to have hit a policeman" is similar in meaning to, but less specific than, "reported". The "it is supposed that" construction is rather less usual, and suggests (to me) some kind of assumption or inference.