This chapter explores the complementarity principle in relation to argument noun phrases other than the subject. It is argued that verbal agreement with pronominal subjects is simply one case of an extremely general agreement process in Welsh. The Maximal Feature Matching Requirement which accounted for the complementary distribution of pronominal (overt and null) subjects and full lexical NP subjects will be shown to extend to these cases. The chapter has three parts. Section 1. provides a general overview of the Welsh pronominal system, and illustrates the range of data to be accounted for. It is shown that pronominal arguments in Welsh are quite generally doubled by an inflectional element. Seetion 2. reviews a number of recent proposals within a GB framework for the analysis of cliticisation and particularly clitic doubled constructions. In Section 3. I present an alternative analysis of clitic doubling in Welsh. It is argued that personal inflection and proclitics should be treated as surface manifestations of the same element, [AGR). With this assumption, the surface distribution of pronominals and full lexical NPs follows from the Maximal Feature Matching Requirement. Section 3. ends with a discussion of a problematic case for this analysis.