I've heard a little about this scale, but how are you graded based on knowledge of the language? To put it more precisely, if there are any formal tests, what are they like?
To quote the ILR website:
"Where can I take an ILR test?"
The answer is: We’re sorry, there is no “ILR test”. The ILR as an entity does not develop or administer tests itself. Many government agencies refer to the ILR Skill Level Descriptions but their tests are administered only within the government context and they are not available to private citizens.
To help you develop a sense of your own ILR proficiency level, the ILR Testing Committee has developed self assessments based upon the ILR scale. Click HERE to access these self assessments, and please also visit the RESOURCES link for other assessment related projects.