A STUDY OF THE EFFECTS OF ENGLISH AS A LANGUAGE OF INSTRUCTION ON LEARNERS’ ACHIEVEMENT IN A NON-LINGUISTIC SUBJECT (MATHEMATICS) AT PRIMARY LEVEL By Saira Maqbool Ph.D Scholar in English Linguistics Supervised By Prof. Dr. Mumana Ghani Chairperson, Department of English Dean, Faculty of Arts Department of English The Islamia University of Bahawalpur 2016