transformational grammar
noun /ˌtrænsfəˌmeɪʃənl ˈɡræmə(r)/
/ˌtrænsfərˌmeɪʃənl ˈɡræmər/
[uncountable] (abbreviation TG)
(linguistics)- a type of grammar that describes a language as a system that has a deep structure which changes in particular ways when real sentences are produced