Definition The Purpose of the Study of Errors

The second is omission of grammatical morpheme. This type is characterised by the absence of an item that does not contribute much to the meaning of the sentence.  Addition Addition is characterised by the presence of an item which must not appear in a well-formed utterance. There are three types of addition. The first is double marking. This type is characterised by the presence of two items or more rather than one in a sentence when only one marker is required. The second is regularization. It is a presence of a marker that should not be added to exceptional items. The third is simple addition error. It is an addition error which is not a double marking nor a regularization.  Misformation Misformation errors are characterised by the use of the wrong form of the morpheme or structure Dulay et al., 1982. There are three types of misformation errors. First is regularization. It is a regular marker which is used in place of an irregular one, as in runned for ran or gooses for geese Dulay et al., 1982. Dulay et al. also call regularization error that falls under the misformation category as overregularization. Second is archi form. It is the use of one form for the several required. Third is alternating form. This error is characterised by the use of two or more forms in random alternation even though the language requires the use of each only under certain conditions.  Misordering Misordering errors are characterised by the incorrect placement of a morpheme or group of morphemes in an utterance. Misordering errors occur systematically for both L2 and L1 learners in constructions that have been acquired, specifically simple direct and embedded indirect question Dulay et al., 1982. 26 The examples of error types based on the surface strategy classification are presented in the table of error types based on surface strategy classification see appendix 4.

3. Comparative Taxonomy

Comparative taxonomy classifies errors based on comparisons between the structure of L2 errors and certain other types of constructions Dulay et al., 1982. This taxonomy has four error categories.  Developmental Errors These are errors similar to those made by children learning the target language as their first language. Example: Dog eat it. It is made by a Spanish child learning English in which he or she makes the omission of the article and the past tense marker.  Interlingual Errors This category concerns with L2 errors that reflect native language structures, regardless of the internal processes or external conditions that influence the errors. Example: the man skinny It is produced by a Spanish speaker reflects the word order of Spanish adjectival phrases. 27