Theory of Second Language AcquisitionThe theory of second language acquisition is relevant to the present study in that itprovides a good explanation why secondary school students make translation errors bothin language structure and meaning. O’Grady; Dobrovolsky; & Katamba (1996: 504-511)explain that both first and second languages have a strong influence on learners’ secondlanguage acquisition. The second language learner always “develops their own version ofthe second language which they speak as they learn called interlanguage” (Spratt;Pulverness; & Williams. 2005: 44). As a consequence, errors are unavoidable andnecessary to language learning. There are two main reasons why learners make mistakes.The first reason is influence from their first language called mother tongue interference.The learners usually transfer the sound patterns, vocabulary and grammatical structures toproduce the target language. Most of the time, this transfer causes errors since the twolanguages do not have exactly the same linguistic elements. The second reason is becausethe learners are experimenting or working out the language. This process is not yetcomplete so the errors naturally come up. This is called a developmental error which alsohappens to learners of the first language and disappears when they develop more with thelanguage. One example of this error is overgeneralization, where learners apply rules ofone language item to another item. For example, learners write goed instead of went.