This book is a study of the syntax and semantics of proportional Most and other majority quantifiers across languages. Based on data drawn from around forty languages, this book reveals the existence of two semantic types of Most: a distributive type, which compares cardinalities of sets of atoms, and a “cumulative” type, which involves measuring plural and mass entities with respect to a whole. On the syntactic side, the most important difference is between non-partitive and partitive configurations. Certain majority quantifiers are specialized for partitive constructions, others are also allowed in non-partitives. We also examine complex majority expressions of the type The Largest Part and nominal quantifiers of the type The Majority. This large scale crosslinguistic investigation qualifies as a piece of typological research that moreover offers several case studies on both well-studied and less investigated languages (English, German, Icelandic, Romanian, Italian, Hungarian, Basque, Latin, Hindi, Syrian Arabic). The proposed analyses raise new theoretical questions regarding issues such as number marking, partitivity, kind reference, (in)definiteness marking, which are crucial issues for linguistic theory. Noteworthy is the attention paid to mass and collective quantification, an under-studied area. We argue in favor of a quantificational analysis of Most, against recent analyses that attempt to derive the proportional interpretation from the superlative, but we adopt a bipartition-cum-superlative analysis for The Largest Part.