(i) The social groups that he mentions are Hindus and Muslims. Yes, these groups were easily identifiable by their dressing, tradition, culture, etc. For instance, Kalam used to wear a cap on his head which identified him as a Muslim. Ramanadha Sastry wore a sacred thread.
(ii) They were not aware only of their differences. They also naturally share friendships and experiences. Kalam’s mother and grandmother would tell events from the Ramayana and from the life of the Prophet as bedtime stories. All his friends belonged to orthodox Hindu families. During the annual Sita Rama Kalyanam Ceremony, his family would arrange boats with a special platform for carrying idols of the Lord from the temple to the marriage site situated in the middle of the pond called Rama Tirtha, which was near his house.
(iii) The author speaks both of people who were very aware of the differences among them and those who tried to bridge these differences. Yes, we can identify such people in the text.
The new school teacher and Sivasubramania Iyer’s wife were very aware of the differences among the social groups, but Sivasubramania Iyer and Lakshamana Sastry tried to bridge these differences.
(iv) Two incidents that show how differences can be created, and also how they can be resolved are explained below:
When Lakshamana Sastry got to know about the way the new school teacher had made Kalam sit on the back bench because he was a Muslim, he asked the teacher to apologize or quit the school. The new teacher not only regretted his behaviour but also was reformed by Lakshamana Sastry’s strong sense of conviction.
Kalam’s science teacher, Sivasubramania Iyer, asked Kalam to his home for a meal. His wife was horrified at the idea of a Muslim boy being invited to her pure kitchen. Sivasubramania Iyer served Kalam food with his own hands and sat down beside him to eat his meal.
The next time he invited Kalam to his home, Sivasubramania Iyer’s wife served him food with her own hands inside the kitchen.