DescriptionThis dissertation concerns two focus particles (jiu, dou) and wh-expressions (shenme ‘what’, na geren ‘which person’) in Mandarin Chinese. These items are systematically ‘ambiguous’ and have played important roles in various aspects of Mandarin grammar. An idea based on alternatives and varieties of alternatives in particular – following Chierchia’s 2013 analysis of the polarity system – is pursued to account for the systematic ambiguities. Unambiguous semantics of jiu, dou and wh-expressions is maintained and ‘ambiguity’ explained through varieties of alternatives interacting with other independently motivated aspects of the structure they occur in. A better understanding of a large array of phenomena that involve these items – exhaustivity, distributivity, questions and conditionals – is achieved.