What other languages do you speak? Maybe someone with the ability to speak that language could help you out.
Have you tried the following?
1. Start from the Installer DVD by holding down "C".
2. Choose your preferred language.
3. Go to the Menu Bar > Utilities > Disk Utility.
4. Select your HDD (hard disk drive).
5. Go to the "Erase" tab.
6. Select Volume Format > Mac OS Extended (Journaled)
7. Click "Erase". And click "okay" or "yes", whatever comes next in the following dialog, so the process can proceed.
8. After all that is done, restart and boot again from the DVD, and try to install Mac OS.
But know, that erasing your HDD will delete all the data on that drive.
Did that help in any way? Or can't you erase your HDD, because you have not backed up yet?