The relation between functionally similar forms is often described in terms of competition. This leads to the expectation that over time only one form can survive (substitution) or each form must... Show moreThe relation between functionally similar forms is often described in terms of competition. This leads to the expectation that over time only one form can survive (substitution) or each form must find its unique niche in functional space (differentiation). However, competition cannot easily explain what causes functional overlap or how form-function mappings will be reorganized. It is argued here that the changes which competing forms undergo are steered by various analogical forces. As a result of analo-gy, competing forms often show attraction, becoming functionally more (instead of less) alike. Attrac-tion can maintain and increase functional overlap in language. At the same time, competing forms are analogically anchored to a broader constructional network. Cases of differentiation typically follow from the relations in that network. Evidence is drawn from the literature and from three corpus-based case studies, addressing attraction and differentiation in English aspectual constructions, English sec-ondary predicate constructions, and in a pair of Dutch degree modifiers. Evidence is provided of a phe-nomenon competition-based accounts could not predict (attraction), and a solution is offered for one they could not very well explain (differentiation). More generally it is shown that the development of competing forms must be understood against their broader grammatical context. Show less