Michael Halliday (born 1925) is a linguist who developed a grammar model, the systemic functional grammar, originally by studing Chinese. His work was an elaboration of the foundations laid by his British teacher J. R. Firth[?]. His seminal paper on this model was published in 1961. The model has been applied to other languages as well as Chinese. It is especially useful for describing non-Indo-European languages.
... is spread out with 29.0% under the age of 18, 5.0% from 18 to 24, 29.0% from 25 to 44, 24.2% from 45 to 64, and 12.7% who are 65 years of age or older. The median age is 39 ...