Introduction:
The postmaster in Rabindranath Tagore's short story "The Postmaster" realizes Ali's feelings through various observations and interactions. This insightful understanding of Ali's emotions develops gradually as the postmaster spends time in the remote village where Ali works as a servant.

Observing Ali's Loneliness:
The postmaster begins to notice Ali's loneliness and isolation in the village. Ali, being a young Muslim boy, is far away from his family and friends. The postmaster observes that Ali spends most of his time alone, engaging in his responsibilities as a servant. This solitude becomes evident when the postmaster tries to initiate conversations with Ali, only to receive short and distant responses.

Witnessing Ali's Homesickness:
As the postmaster spends more time with Ali, he witnesses moments of homesickness in the young boy. Ali often gazes longingly at the letters sent from his family, reading and rereading them in an attempt to find solace in their words. The postmaster notices Ali's eyes welling up with tears as he reads these letters, which indicates his longing for his loved ones and his yearning to be back home.

Understanding Ali's Desire for Education:
The postmaster also realizes Ali's deep desire for education. Despite being a servant, Ali shows great enthusiasm for learning and often listens intently when the postmaster reads out stories or poems to him. The postmaster observes the spark of curiosity and passion in Ali's eyes, which further confirms his yearning for knowledge and education.

Recognizing Ali's Attachment to the Postmaster:
As time passes, a bond develops between the postmaster and Ali. The postmaster becomes a fatherly figure to Ali, filling the void left by his absence from his own family. The postmaster notices Ali's increased reliance on him for companionship and guidance. He realizes that Ali finds comfort in their conversations and seeks solace in their shared moments.

Conclusion:
Through keen observation and genuine empathy, the postmaster in "The Postmaster" gradually realizes Ali's feelings of loneliness, homesickness, thirst for education, and attachment to him. This understanding of Ali's emotions adds depth to the narrative and highlights the universal need for human connection and understanding.

When his daughter felt ill and he was waiting for her letter to come then he realised about Ali's feelings.