 Thus, if the developmental paths of child and adult L2 learners overlap significantly it is likely that the basis of difference is the shared experience they have with their L1.If, however, if they follow different developmental paths this would seem to support the claim that adult L2 learners do not have access to UG; their learning must instead be due to other factors.Finally, in multilingual acquisition, if it were shown that adult L2 learners can transfer POS properties only available from their L2 to their L3 or L4 etc.