premise: The family wheeled Grandma out onto the lawn in her wheelchair , where her 100th birthday celebrations were taking place . Grandma could n't speak very well , but she would write notes when she needed to communicate . After a short while , Grandma started leaning over to her left , so some family members grabbed her , straightened her up , and stuffed a pillow on her left side . A short time later , she started to lean over to her right , so again the family straightened her up and stuffed a pillow down on her right side . What 's a possible reason Grandma could n't speak very well ?
hypothesis: Because she was wheeled out onto the lawn .