transformacje dwie

Hej!

Czy mógłby mi ktoś pomóc i rozwiać moje wątpliwości?

1)There were once thought to be canals on Mars.

It was once thought that there were canals on Mars.

Dlaczego nie może być "It was once thought that there ARE canals on Mars"?

2) She vaguely remembers that she was knocked down by a motorbike.

She has vague memories of being knocked down

No właśnie, czy nie mogłoby być 'She has vague memories of HAVING BEEN knocked down?'

Pozdrawiam

1)There were once thought to be canals on Mars.
>
>It was once thought that there were canals on Mars.
>
>Dlaczego nie może być "It was once thought that there ARE canals on
>Mars"?

It can't be like that because, in that case, people were thinking about canals on Mars in the past, not now. Besides, the transformation is meant to be made from the original sentence - I know that people can still think that there are canals on Mars now.

2) She vaguely remembers that she was knocked down by a motorbike.
>
>She has vague memories of being knocked down
>
>No właśnie, czy nie mogłoby być 'She has vague memories of HAVING BEEN
>knocked down?'

In that case the only possible answer is to use the present continuous passive. I can't explain you why it is so but I'm certain about that.

thanks a million :)

tez jestem ciekawa. Czemu nie moze byc HAVING BEEN KNOCKED?

Ktos sie podejmie wytlumaczenia?

a memory is a recollection of something that happened in the past. There's no need of using a perfect gerund, which conveys the same information. What I have said does not mean that a perfect gerund would be absolutely ungrammatical in this situation.

Musisz czas gramatyczny dopasować do tego zdania co Ci podali. Po polsku zdanie typu 'on wiedział ze robi głupio' ujdzie, ale po angielsku niekoniecznie, musi byc 'on wiedział że robił głupio' -> analogia do pierwszego zdania. A w drugim nie masz żadnej podstawy żeby present perfect wprowadzać :)

Makes sense...