Psycholinguistic what is psycholinguistic? 1-pyscholinguistic is the study of the cognitive process of language acquisition and use. 2-The scope of psycholinguistic includes language performance under normal circumstances and abnormal ones,eg brain damage. 3- The focus of psycholinguistic has been on L1 in studying children acquisition L1 and research on adult comprehension and production.

Psycholinguistic recently extend the study of language processing on bilinguals who acquiring or who using more than one language. A.Bilinguals provide a similarly universal account of cognitive mechanism that underline language performance. B. The use of two or more language provide a powerful tool for investigating issues of representation and processing.

Here one some selective views of recent of research on second (L2) language acquisition and competent bilingual performance.

First: the cognitive process of individual acquiring proficiency in l2 share common basis with process of component bilingual. Second: the mechanism are generally universal across languages although there are differences depending on structural properties of language.eg, difference in alphabet system of L1 and L2. Third: the same cognitive resources are available universally to all learners although there may be some differences.

Cognitive models: In psycholinguistic,researchers try to develop models to describe and predict specific linguistic beha viour,try to specify how language is processed in our brain. William levelt model Levelts speaking model aims describing development of communicative intentions to sound process in three components 1-conceptualizer:communicative intentions are turned into sth that can be expressed in human language. 2-formulator:here isolated words and meanings are turned into sentences. 3-articulator:the above sentences translated into sounds by this component.

Levelt model is largely lexically based lexical items consist of two parts: The lemma, lexical entrys meaning and syntax are represented. The lexeme, the morpho –phonological properties are presented. The selection of the lemmas with their meaning and syntax leads to formation belonging to formation of the surface structure. As surface structure is being formed,the morpho- phonological information belonging to the lemma is activated and encoded. The lemma can be said link between meaning and form.

The lemma/lexeme distinction figures in most theories of the language.We are not sure how this matching takes place and where Evidence for this distinction comes form occurring speech errors, aphasia “top of the tongue” phenomena. levelts speaking model is primarily a model mono-lingual speaker

Poulisse mentions following factors that have to be taken into account if we want to turn monolingual into bilingual. L2 knowledge is typically incomplete.since L2 speakers generally have fewer words and rules than L1speakers so they avoid words and structures which they feel uncertain. L2 speech is more hesitant and contains more errors and slips depending on the level of proficiency of the learners,because of less automaticity. L2 speech often carries trace of L1 so they may switch to their L1,deliberately (motivated switch )or unintentionally (performance switch).

Keeping language apart There are proposals suggested that there are switches controlling the input and output of different languages According to Paradis,words,syntactic rules or phonemes from a given language form a sub-set of the total inventory and each sub-set can be activated independently our claim is that the subset hypothesis may explain how languages in bilinguals may be apart.

Language choice : In levelts description :the lemma consists basically of three parts: The semantic specification :is “the set of conceptual conditions under which the lemma can be appropriately used “ The syntactic information,refers to the syntactic category of lemma and its grammatical functions. The third type of information is the lemma is a pointer to lexeme. lexemes contain phonological specifications of a lemma and the morphological make up,although the exact relation between the lemma and the lexeme is not entirely clear.