Keijzer (2007) conducted a study on the attrition of Dutch in Anglophone Canada. She finds some evidence that later-learned rules, such as diminutive and plural formation, indeed erode before earlier learned grammatical rules. However, there is also considerable interaction between the first and second language and so a straightforward 'regression pattern' cannot be observed. Also, parallels in noun and verb phrase morphology could be present because of the nature of the tests or because of avoidance by the participants. In a follow up 2010 article, Keijzer suggests that the regression hypothesis may be more applicable to morphology than to syntax.