In my dissertation on leftward association of English and German focus particles, I investigate the following overall research questions: How strong is the c-command relation between focus particles and their associated focus? Is their relation fixed or are there factors which can license leftward association? In my study, I focus on the English particles "only" and "even" and the corresponding German particles "nur" and "sogar". These particles preferably c-command their associated focus constituent (as in "Only SAM will eat chocolate). It is controversial in the literature how strong this c-command relation is and whether leftward association of these particles is acceptable (as in "SAM will only eat chocolate"). To my knowledge, my study provides the first experimental investigation dealing with this phenomenon. In the analysis of examples from everyday language and in various acceptability judgment studies, I identified the following factors which license leftward association of the German particles under consideration: (i) prosody, (ii) speaker evaluation, and (iii) special emphasis. I conclude that the c-command relation between focus particles and their associated focus is strong but not fixed in such a way that leftward association is impossible, as there are factors which improve and license this construction. Moreover, German examples I collected from spontaneous speech provide evidence that leftward association of the German particles under consideration occurs in spoken language. I base my explanations of the data on theories dealing with emphatic syntactic constructions and on theories dealing with salience and cognitive prominence. I propose an account which combines information structure, pragmatics, and processing