This study is aimed at identifying the role of analogy in grammaticalization and proving the need to look at grammaticalization on the language processing level as well as on the language output level. Looking at a change on the processing level throws a different light on the common notion that grammaticalization follows gradual linear path, which is crucially determined by reanalysis. This investigation displays that owing to was attracted to the preposition category by analogy to the already existing deverbal preposition construction in English, and due to was also formed by analogy to owing to on the basis of semantic similarity.