This study investigates characteristics of the notional subject consisting of a noun phrase headed with a definite article (hereafter, ‘the + NP’) in existential there constructions. According to the previous literature (e.g., Milsark, 1974), definite NPs do not occur as notional subjects in existential there constructions; this characteristic is widely known as the ‘Definiteness Restriction.’ In reality, however, we sometimes come across existential constructions that apparently violate this restriction. Through a quantitative analysis of real language data extracted from the British National Corpus (2000), the following points were revealed. (1) Approximately 80-90% of notional subjects were indefinite NPs and 5% were ‘the + NPs.’ (2) Many ‘the + NP’ subjects could be regarded as semantically indefinite NPs that were cataphorically modified with appositive that-clauses and of-phrases, etc. (36% in the spoken and about 66% in the written data). (3) Anaphoric and exophoric uses of ‘the + NP’ subjects also occurred, particularly when existential constructions served to list entities that the subjects refer to, to emphasize the existence or non-existence of an entity, to direct the hearer towards an entity, and to focus on the occurrence of an event. (4) Distinctive differences were observed across spoken and written registers in the uses of the definite article, the types of postmodification, the types of discourse functions, and the abstract/concrete distinction of noun heads of ‘the + NP’ subjects.