In linguistics, according to J. Richard et al., (2002), an error is the use of a word, speech act or grammatical items in such a way that it seems imperfect and significant of an incomplete learning (184).
However, the attempts made to put the error into context have always gone hand in hand with either [language learning and second-language acquisition] processe, Hendrickson (1987:357) mentioned that errors are ‘signals’ that indicate an actual learning process taking place and that the learner has not yet mastered or shown a well-structured [linguistic competence|competence] in the target language.
The occurrence of errors not only indicates that the learner has not learned something yet, but also gives the linguist an idea of whether the teaching method applied was effective or needs to be changed.
In other words, errors are thought of as indications of an incomplete learning, and that the speaker or hearer has not yet accumulated a satisfied language knowledge which can enable them to avoid linguistics misuse.
Error analysis approach overwhelmed and announced the decline of the Contrastive Analysis which was only effective in phonology; and, according to J. Richard et al. (2002), EA developed as a branch of Linguistics in the 1960s and it came to light to argue that the mother tongue was not the main and the only source of the errors committed by the learners.
Error can be classified according to basic type: omissive, additive, substitutive or related to word order.
In particular, the above typologies are problematic: from linguistic data alone, it is often impossible to reliably determine what kind of error a learner is making.
The example, provided by J. Richard et al. (2002) ‘’ the incorrect French sentence Elle regarde les (“She sees them”), produced according to the word order of English, instead of the correct French sentence Elle les regarde (Literally, “She them sees”).
this kind of errors have been committed while dealing with regular and irregular verbs, as well as the application of plural forms.
This kind of errors is committed through both of Omission and addition of some linguistic elements at the level of either the Spelling or grammar.
A. Mahmoud (2014) provided examples based on a research conducted on written English of Arabic-speaking second year University students: Developmental errors: this kind of errors is somehow part of the overgeneralizations, (this later is subtitled into Natural and developmental learning stage errors), D.E are results of normal pattern of development, such as (come = comed) and (break = breaked), D.E indicates that the learner has started developing their linguistic knowledge and fail to reproduce the rules they have lately been exposed to in target language learning.
Errors of overproduction: in the early stages of language learning, learners are supposed to have not yet acquired and accumulated a satisfied linguistic knowledge which can enable them to use the finite rules of the target language in order to produce infinite structures, most of the time, beginners overproduce, in such a way, they frequently repeat a particular structure.
clinical elicitation involves getting the informant to produce data of any sort, for example by means of general interview or writing a composition.