This book deals with the interpretation of adverbially quantified sentences containing definite DPs and Free Relatives (FR) Thereby, it concentrates on the origins of Quantificational Variability Effects (QVEs), i.e. readings according to which the respective quantificational adverb seems to quantify over the individuals denoted by the respective DP/FR. QVEs are usually discussed only in connection with singular indefinites and bare plurals. This book therefore provides the first comprehensive account of QVEs with definite DPs and Free Relatives (while also discussing singular indefinites and bare plurals). Presenting new empirical observations and arguments for the assumption that Q-adverbs quantify over situations exclusively, it is also an important contribution to the theoretical debate concerning the quantificational domain of Q-adverbs.. It is of interest to linguists working in formal semantics and the syntax-semantics interface as well as to philosophers of language who are interested in adverbial quantification and situation semantics. Furthermore, it offers an introduction to the core issues of situation semantics and adverbial quantification and is therefore accessible to graduate students interested in these topics.