This paper intends to test the three principles of MLF model , that is ,’the uniform structure principle’ , the morpheme order principle ‘ , and ‘ the system morpheme principle’(Mayer –scotton,2002) with persian English data .it also determines whether or not persian English is a case of “classic code –switching”( Mayer –scotton,2002) Muysken(2011)defines code switching as ”the use of more than one language during a single communicative event. ”switches are typically classified according to the place they occur. Mayers-scotton(2006) considers a clause as the best unit of analysis of bilingual data. We have also overlooked the issue of bilingualism and its classification according to different views to typify our case study subject in this study we test matrix frame model of code-switching with Persian English data through a case study approach from the daily speech of a 3 year old boy to see whether the data confirm the principles of the model or not .A Persian English corpus was provided from the daily speech of this bilingual boy during a week .then the data were exemplified and illustrated by the principles in greater detai l ,followed by the results of an analysis relating to each principle .in general , we will show that the principles do appear to be reflected in our data. In other words the three principles of MLF model, that is ,the Matrix Language principle , asymmetry principle ,and uniform structure principle were verified. The results of the analyses suggest general support for the four principles of the MLF model. It is also concluded that Persian English code-switching does seem to be a ‘classic’ case of code-switching in the case of the child language acquisition that can be tested in other cases to give more proof.

Keywords