Systemic functional linguistics is general linguistics to describe universal features of the language and applied to solve problems (appliable and problem-oriented)
There are two schools in the study of linguistics, namely formalism and functionalism. The latter connects the forms and meanings of the language.
SFL is being developed in an evolutionary approach. So to speak, existent theories are continuously examined by practice and modified.
Halliday (1994: xiv): "A language is interpreted as a system of' meanings, accompanied by Ibnns through which the meanings can be realized.”, which means, the language is a system used to express the meanings by its forms.
The System means the language is a paradigmatic entity consisting of features of which the language can choose one or more than one for a certain entry condition. (入列条件)
Or(析取) relation means choosing only one feature, like the voice for an entry condition. A clause can be constructed in either active voice or passive voice.
And(合取), means having two or more features, like the metafunctions of a clause.
The System network means an entry condition has a couple of systems that can exist in either “or” or “and” relation.
Conflation means the constituent of different functions of a clause may overlap.
Ordering of a clause can alter the function of a clause.
A text as an artifact means the text is used to analyze the application.
A text as a specimen means the text is used to summarize the general feature of the language.
SFL: Fields of activity and degree of generalization
4. Theorizing language
3. Typologizing languages (based on existing descriptions)
2. Describing a language (based on texts, using an existing theory)
1. Analyzing texts (using an existing description)