Take a child learning the grammar of her language, L. Figure 2 represents the 5 possible relations that might obtain between the language generated by her current hypothesis, H, and that generated by the target grammar, L. (v) represents the end point of the learning process: the learner has figured out the correct grammar for her language. A learner in situation (i), (ii) or (iii) is in good shape, for she can easily use the pld as a basis for correcting her hypothesis as follows: wheneve