Other residential schools soon followed, such as the "School for Deaf and Dumb Boys" at Mysore, founded in 1902, a school in Dehiwala in what is now Sri Lanka, founded in 1913, and "The Ida Rieu School for blind, deaf, dumb and other defective children", founded in 1923 in Karachi, in what is now Pakistan. While a few students who were unable to learn via the oralist method were taught with signs, many students preferred to communicate with each other via sign language, sometimes to the frustration of their teachers. The first study of the sign language of these children, which is almost certainly related to modern IPSL, was in 1928 by British teacher H. C. Banerjee. She visited three residential schools for deaf children, at Dacca, Barisal and Calcutta, observing that "in all these schools the teachers have discouraged the growth of the sign language, which in spite of this official disapproval, has grown and flourished." She compared sign vocabularies at the different schools and described the signs in words in an appendix. A rare case of a public event conducted in sign language was reported by a mission in Palayamkottai in 1906: "Our services for the Deaf are chiefly in the sign language, in which all can join alike, whether learning Tamil, as those do who belong to the Madras Presidency, or English, which is taught to those coming from other parts." Grammar Despite the common assumption that Indo-Pakistani Sign Language is the manual representation of spoken English or Hindi, it is in fact unrelated to either language and has its own grammar. Zeshan (2014) discusses three aspects of IPSL: its lexicon, syntax and spatial grammar. Some distinct features of IPSL that differ from other sign languages include: 1) Number Signs: The numbers from zero to nine are formed in IPSL by holding up a hand with the appropriate handshape for each number. From one to five the corresponding number of extended fingers forms the numeral sign, whereas for zero and the numbers from six to nine special handshapes are used that derive from written numbers. Ten may either be expressed by two 5-hands or by ‘1+0’. (Zeshan, 2000) 2) Family Relationship: The signs for family relationship are preceded by the sign for ‘male/man’ and ‘female/woman’. 3) Sign families: Several signs belong to same family if they share one or more parameters including handshapes, place of articulation and