[A contact language] must be adequate to the function it … require more linguistic complexity. At the same time, … [adults] who have to learn to speak it. … Research into language acquisition--both of the first and … age of about six onwards. … after the crucial cut-off point--the so-called 'critical stage'--has … a language. … [p. 100] Put another way, this means that the … requirements of child language-learning strategies.
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