So in the 15 years they started using statistical methods for understanding language, googles ability to understand language is at about an 8 year olds level. So it is learning about half as fast as a human child. Not bad and an excellent opportunity to predict it's growth rate for the future.

If this is a linear learning curve, in another 15 years it should just start to be able to 'understand' the nuances of Shakespeare and Ulysses among others.