T-unit

In linguistics, the term T-unit was coined by Kellogg Hunt in 1965. It is defined as the "shortest grammatically allowable sentences into which (writing can be split) or minimally terminable unit." Often, but not always, a T-unit is a sentence.

More technically, a T-unit is a dominant clause and its dependent clauses: as Hunt said, it is "one main clause with all subordinate clauses attached to it" (Hunt 1965:20). T-units are often used in the analysis of written and spoken discourse, such as in studies on errors in second language writing. The number of error-free T-units may be counted, as in Robb et al. (1986), or changes in accuracy per T-unit over drafts of compositions may be measured (Sachs and Polio, 2007).