Recall that θ-marking takes place in the configuration (5) [(i) [γ...α...β...] (ii) [γ...β...α...]], where β as well as α is an immediate constituent of γ, assuming α to have appropriate properties determined ultimately by the lexicon. There are two cases: (i) γ = ᾱ; (ii) β is the subject of α. In case (i), α is a lexical element that subcategorizes and hence θ-marks β; let us say that in this case, α "directly θ-marks" β or a category "C" such that it or its trace occupies the position β.
- Chomsky (1993), a pag.38