The choice of object language of College Chinese textbook and textbook compilation;

Metalanguage is second-order language which is used to describe or explain lan- guage itself,while object language is first-order language which is used to describe things in ordinary life.

In Mo_ching ,there are not propositional form and inference form expressed as object language,and there are only inference ways reflected by typical specific inference,but there are lots of logical rules expressed by metalanguage,which makes clear that Mo_ching logic has come to enter the stage of formal logic.

Probing into some important linguistic differences between English and Chinese,it suggests that translation teaching be conducted through highlighting linguistic contrast in language teaching.

From the ascepts of the nature,cognitive model,restriction principle and interactive relationship between metonymy and metaphor,analyzes and explains the mouth/teeth/lip/tongue-speech,discusses the national difference of mouth/teech/lip/tongue-speech by language comparison.