Salam!
While teaching the conditional, one is met by many intelligent questions on the part of the pps. Moreover, situations are sometimes real and sometimes unreal.
In order not to mislead the pps, some examples should be provided in both cases.
The following may make it easier to us to make things clearer to our pps.
http://www.mediafire.com/?mm0qyk5n0cd
You'll find more about many other points through this link:
http://www.englishpage.com/index.html
Wish you'll find it useful.
Thanks a million for your attention.
Salam!