Tsang & Stokes (2001) investigated the development of syntactic awareness, children’s emerging ability to reflect upon the internal grammatical structure of sentences, in Cantonese-speaking children in both judgment and revision tasks and found that children scored significantly higher in judging sentences with word order changes than those with morphological violations, which was totally converse in English. Thus, we should admit that syntactic awareness is very much affected by language-specific characteristics. Besides, there also seems to be a significant age effect on subjects' performance in syntactic awareness tasks. Additionally, Susan Jerger et al. (1981) indicated that Typically Developing (TD) children demonstrate age-related improvements in language processing (i.e. they become faster processors). They found that 3-6 years old children’s performance for Pediatric Speech Intelligibility (PSI) Format I and Format II sentences was significantly different and these performance differences were related to chronological age and receptive language ability. Meanwhile, Ann Fathman (1975) indicated that there was some relationship between age and rate of learning of syntax and the language proficiency of children improves with age. Regardless of language status, older children produced faster reaction time than younger children. The results of logistic regressive analysis (Bernhard Richter et al., 2002) indicated that the speech production measured depended decisively on age at implantation, age at time of test, speech production before implantation, and additional handicaps. However, Safaa Refaat El Sady et al. (2013) argued that children with Attention deficit-hyperactivity disorder (ADHD) showed a significant delay in language development. And there was no difference between ADHD children and TD children in total language age, semantics, pragmatics and expressive language age. The only scale that showed difference between children with ADHD and controls was the receptive language age and receptive age quotient. 

All results seem to suggest that receptive language age plays an important role in receptive sensitivity on the development of syntax among 3-6 years old children. Therefore, it is reasonable to ask whether the deliberate development of receptive language skills will facilitate acquisition of productive speech. And we should take receptive language age into consideration when assessing the effects of receptive sensitivity during the development of syntax among 3-6 years old children.