1. Subset principle

2. Assumes construction of more conservative grammar (Y), learner only moves to larger grammar (X) on basis of positive evidence XX Y X

3. Dative alternation: Most languages allow structures such as: – John gave the necklace to Mary. – John explained the problem to Paul. – John donated the book to the library. Some also allow for alternation (but not of all verbs): – John gave Mary the necklace. – *John explained Paul the problem. – *John donated the library the book.

4. When learning a language, L1 learners will assume the more constrained version, the subset, until they receive enough evidence to confirm that the superset is possible, and the rules of the superset.

5. Question for L2: Do learners still have knowledge of the subset principle, or do they transfer supersets from their L2, needing negative evidence when the L1 is a subset of the L2?