What’s contraction? Contraction is the process of taking two free morphemes and making one bound in order to create one morpheme. In short: two words are joined into one. To the native English speaker, contracted and non-contracted forms are semantically equivalent. However, there are certain instances where contraction is not permitted. For example, the sentence, “I’m happy, but she’s not,” is perfectly grammatical, but “*I’m not happy, but she’s,” is ungrammatical. Why should this be? Although the contracted and non-contracted forms are semantically equivalent, they differ structurally. To answer the question of what conditions allow for contraction, existing arguments on the topic will be discussed. However, the problem with these arguments is that they are too broad or they do not cover all types of contraction. This proposal offers a solution by claiming that there are two procedures for contraction in English. In this proposal, the contracting morphemes determine which procedure is performed. In finite contraction, the morphemes bear tense. This means that the bound morphemes must contract and attach themselves, as prefixes, to hosts located on the right of the morphemes. However, in non-finite contraction, the morphemes are tenseless. As a result, they must contract and attach themselves, as suffixes, to hosts located on the left of the morphemes.