  Both hypotheses are adequate to account for the data the learner has  so far encountered. To any unbiased scientist, though, H1 would  surely appear preferable to H2, for it is simpler — it is shorter, for one thing, and does not refer to theoretical  properties, like being a NP, being instead formulated in terms of  ‘observable’ properties like word order. Nonetheless, H1  is false, as is evident when you look at examples like (3):