我们乔老先生在1986年的《语言的知识：本质、源头和使用》一书里，提出了现代句法研究最重要的原则——投射原则！投射原则说的是，词库这个大脑信息库，包含的所有信息，必须在句法的所有层面表现出来。
wǒmen Qiáo lǎoxiānsheng zài 1986 nián de 《 yǔyán de zhīshi ：běnzhì 、yuántóu hé shǐyòng 》yī shū lǐ ，tíchū le xiàndài jùfǎ yánjiū zuì zhòngyào de yuánzé ——tóushè yuánzé ！tóushè yuánzé shuōdeshì ，cíkù zhè ge dànǎo xìnxī kù ，bāohán de suǒyǒu xìnxī ，bìxū zài jùfǎ de suǒyǒu céngmiàn biǎoxiàn chūlái 。
Old Mr Chomsky in his 1986 book 'The Knowledge of Language: Its Nature, Origin and Use' proposed the most important principle of contemporary syntactic research - the projection principle! The projection principle states that lexical structure, this repository of data in the brain, contains all the data, and must be represented categorically at every syntactic level.