Pupils who speak English as a first language are in the minority in 13 out of London’s 33 boroughs, according to official figures released Tuesday. Fifty-six percent of children in elementary schools in inner London do not speak English as their first language. Throughout the country, English is not the mother tongue to one in seven elementary-school-aged children. Such high numbers of inexperienced, and in many cases, incapable, English speakers is putting a heavy burden on Britain’s education system. Far more disturbing than this, though, is that it shows how much immigration is changing Britain. The data, from the Department...