I'm with RichM. English is described in dictionaries and such as it is currently spoken (or believed to be spoken) by a reasonably well educated person. However, i quote from the Concise Oxford 2...ussage constantly changing (so) the distinction between right and wrong is sometimes difficult to establish. English is not monitored by any single authority; established usage is the principal criterion"

Johnson described his early dictionaries as 'descriptive not prescriptive'

The language lives and changes day by day

Stu