When a language provides multiple syntactic options for conveying the same semantic content, these options generally serve distinct discourse functions. In some cases, however, they serve the same discourse function while being in complementary distribution syntactically. This article argues that in these instances, the syntactic variants constitute alloforms of a single, more abstract construction. Pairs of such alloforms include inversion and long passives in English and two forms of postposing in Italian. Moreover, English inversion is argued to be an alloform of both preposing and postposing. This account explains the distributional difference between alloforms of a single construction and complex structures built up of multiple distinct constructions. Finally, the report considers the ramifications of this account for linguistic theory in general and the notion of a ‘construction’ in particular.