1.From that day forward, Helen Keller began to master language.
从那天开始,海伦凯勒开始学习语言。
2.In the primary period , students should also learn some grammar knowledge to help them master language firmly and definitly .
小学阶段,也必须掌握一些语法知识以帮助小学生牢固地、正确地掌握语言。