Abstract:The historical origin of the English syntactic sequence "subjectively grammatical + semantic elements" has been researched in English historical linguistics, but opinions are far from being unified.This paper reviews the related studies and points out that its formation is principally related to subjectivization and the fixation of SVO order.It is found that when S is fixed at the pre-verb position, it becomes the semantic anchor of such subjective elements as modal verbs, the auxiliary have, the V- ingand the passive voice; that case-syncretism, case-dropping and the weakening of information structure are important for the development of SVO order; and that the post-verbal position of particles and the birth of the pseudo subject (object) are also functional for the development of the syntactic sequence "Subjectively Grammatical +Semantic Elements".