Read the following passage carefully and answer Questions Up to the age of 12 all the knowledge I gained was through Gujarati, my mother tongue. I knew then something of Arithmetic, History and Geography. Then I entered a High School. For the first three years the mother tongue was still the medium. But the schoolmaster's business was to drive English into the pupil's head. Therefore more than half of our time was given to learning English and mastering its arbitrary spelling and pronunciation. It was a painful discovery to have to learn a language that was not pronounced as it was written. It was a strange experience to have to learn the spelling by heart. For the first three years it was comparatively plain sailing. The pillory began with the fourth year of my school. Geometry, Algebra, Chemistry, Astronomy, History and Geography-all were to be learnt in English. The tyranny of English was so great that even Sanskrit or Persian had to be learnt through English, not through the mother tongue. It did not matter to the teacher if a boy spoke bad English which he could neither pronounce correctly nor understand fully. Why should the teacher worry? His own English was by no means without blemish. The result was chaos. I know now why I took four years to learn of Arithmetic, Geometry, Algebra, Chemistry and Astronomy. If I had not to learn them through English but Gujarati, my grasp of the subjects would have been easier and clearer. My Gujarati vocabulary would have been richer. I would have made use of such knowledge in my own home. This English medium created an impassable barrier between me and the members of my family, who had not gone through English schools. I was fast becoming a stranger in my own home.

"His own English was by no means without blemish." This means