@@ As for the first language acquisition of the head-initial relative clauses, it is generally held that 1) children acquire relative clause quite late: most of the relative clauses produced by Children of less than 6 (maybe even 8) years old are different from those produced by adults and therefore ungrammatical (for example, children often use resumtpive pronouns or nouns in the places where they are forbidden in the adultsˇ grammar), and Children of less than 6 (maybe even 8) years old cannot understand such relative clauses as object relative clauses (Ors for short)2both production and comprehension of Ors are harder/later than that of subject relative clauses (Srs for short), for example, Contemori & Garraffa (2010) hold that only 50％ (chance level) children of 3冾5 years old can understand Orsbut in their elicitation experiment 79％ 3-year-old children can produce and understand Srs; 3) in production, there appears to be a tendency for children of five years old to avoid Ors altogether, in favor of the production of an privileged alternative structure, that is, Passive Object Relatives, and this transformation increases with age until it happens in almost 90％ of the cases (Labelle 1996; Arosio, Adani 2008; Belletti & Contemori 2010; ; Belletti 2010, Costa, Lobo & Silva 2011, etc.).