Errors of a language learner

Errors may occur in the speech or writing of a second or foreign language learner. An error is the use of a linguistic item in a way which, from the viewpoint of a native speaker, is regarded as faulty, or as the result of incompetent learning. 

Errors have been classified into various types. When an error results from incomplete knowledge . it is called an error. When it is made by a learner due to fatigue, carelessness, or lack of attention, it is called a mistake. 

When an error belongs to vocabulary it is called a lexical error, when it is in pronunciation it is called a phonological error, and when it occurs due to lack of grammatical knowledge, it is a syntactic error. When an error is due to the misunderstanding of a speaker’s intention or meaning it is called an interpretive error, and when its is due to the production of wrong communicative effect, it is a pragmatic error. 

Sometimes an error occurs in the use of a major element of sentence structure. That makes it difficult or impossible to understand. Such an error is called a global error. An error in the use of a first or second language learner may be the result of a normal pattern of development. Such an error is called the developmental error. So errors of a language learner may be of different classes.