Stage 1: the BPT behaves as a full noun phrase both morphosyntactically and syntactically. 
Stage 2: the BPT may optionally display reduced behavior morphosyntactically (loss of agreement) or syntactically (constraints on word order, elision of the possessive pronoun).
Stage 3: the BPT shows constrained syntactic behavior, in the sense that it must be coreferential with the subject, is confined to one particular function within the clause and may not undergo word order permutations such as topicalization.
Stage 4: the BPT does not behave morphosyntactically as a noun phrase anymore, but rather has the properties of a pronoun.
	Что проверяется на корпусных данных?
- (N=2360) + современные корпусные данные
- (i) their grammatical function within the clause
- (ii) frequency of occurrence with respect to intransitivization
- (iii) frequency of modification
- (iv) frequency of non-reflexive anaphoric uses
- (v) frequency of number agreement between the reflexive and the subject
- (vi) frequency of occurrences as opposed to ‘weak’ reflexives.
	
		Разнонаправленные тенденции демонстрируют грамматикализацию, характерную для рефлексивных конструкций:
- Увеличение распространенности рефлексивных конструкций с buru по сравнению с другими рефлексивными конструкциями
- Уменьшение количество случаев согласования
Аргументы против:
- Уменьшение случаев объектной позиции
- Увеличение (редких) случаев субъектной позиции