This paper resuscitates the idea of positing parallel structures in phonology and syntax, an idea which was first presented in detail by Glossematics in the 40's and later taken up by the dependency grammarians in the 80's. Its resuscitation here is the result of analysing the initial levels of syntax and phonology in terms of monovalent components which are subject to identical laws of government and dependency.
First it is shown how it is possible to analyse the ultimate thematic constituents at the syntactic level in terms of single or complex monovalent case components. Subsequently , it is shown how a similar analysis is appropriate for the description or vowel quality. This parallelism leads to the formulation of a stronger version of a more general constraint. This constraint, which has been termed the structural analogy assumption, imposes restrictions on the construction of grammars in general.