As societies adopt a written language for cultural reasons , their grammars often change .
一个社会往往因为文化的原因而选择某种语言作为书面语，其语法则时有变化。
The speech recognizer cannot have that many grammars active at once .
语音识别器不能同时使用很多语法。
It is widely believed that every word has a correct meaning , that we learn these meanings mainly from teachers and grammarians , and that dictionaries and grammars are the supreme authority in matters of meaning and usage .
Moreover , bilingual infants appear to learn the grammars of their two languages as well as babies learning a single language , even when the two languages are as different from one another as english and japanese , or english and punjabi .
