[nshubin]

Thanks, Andrew,
The point is that in Russian (our native language) both of the tenses are expressed the same way - PAST. We have only one past tense. To show them the difference between Past Simple and Present Perfect I need some pictures with the result of the action or connection with the present time, you see?
Games or worksheets are very desirable.
Anyway, thanks a lot. I will try.
Natasha