(a) children’s L1 is important for their overall language and cognitive development and their academic
achievement;
(b) if children are growing up with one language, educational provisions need to support them in becoming
highly profi cient in that language before engaging in academic work in L2; and
(c) becoming highly profi cient (e.g., achieving CALP, as reviewed earlier) appears to take six to eight years
of schooling (i.e., at least until the end of primary year six).