This chapter looks at three sets of predictions that distinguish the Truncation Hypothesis from the Missing Inflection Hypothesis, relating to finiteness, to the nature of subjects and to word order. It considers prediction for the distribution of null subjects, subject clitics and case-marking on DPs and pronouns. For the rest of this chapter, when analysing the child L2 French data, it concentrates on the first 18 months, that is, the period during which finite and nonfinite forms coincide. Thus, it is conceivable that the adult null subjects are in fact pro, rather than null constants, which would explain their occurrence in CPs and their failure to coincide with root infinitives. Nevertheless, despite these shortcomings, we believe that the data examined here are suggestive of the possibility that variation in use of inflection in child L2 acquisition. This is somewhat different in nature from variation in adult acquisition, truncation predominantly accounting for the child performance and missing inflection for the adults.