some questions on られる form


im self learning japanese and having problems understanding られる or 受け身 form of
verbs.

I am wondering why the following sentences are not ok:

> 私は石に頭に落ちられた
>
> トムは交差点の真ん中で車に止められた

However it says

僕は雨に降られた is ok.

Can anyone explain why this is the case?




Are you taking those examples from "A Dictionary of Basic Japanese Grammar"?
The book itself says the reason:  
"In indirect passive sentences the agent of the event is usually animate and
the action is volitional".

This kind of passive is usually used when you suffered the actions of someone
else.

When you say 僕は雨に降られた it is as if you are putting the blame on the rain, as if
the rain wanted to hurt you on purpose.  
Of course that is not true, so usually you cannot use that kind of passive for
inanimate objects.

