Empirical research is beginning to provide an answer to this question. A number
of studies suggest that UG principles are available to the second language
learner and that parameter resetting is possible (d. White, 1989). Some learners
clearly do attain complex and subtle knowkdge which does not derive solely
from the L1; this is unexplained if 12 learning proceeds only by means of general
cognitive strategies such as hypothesis-testing and problem-solving. There are
clear suggestions that UG must be involved in second language acquisition.