Question

why did Helen break her doll? Explain i brief.

Answer 1

Helen could not understand the true meaning of what Anne Sullivan was trying to tell her.Out of this frustration,she destroyed the doll.

Answer 2

Helen was sensitive as a child. The repeated attempts and failures to learn the meaning of "mug" and "water" had frustrated her and she dashed her doll against the floor. To understand the psyche of a blind and deaf child, an average person must see her frustrations  as much intense that the disappointment felt by a "normal" child.