The linguists state that there are developmental sequences when the learners acquire second language. Schumann (1979), for instance, found that there were predictable sequences in negation in second language learning regardless the learners’ first language background. Krashen (1972), in his monitor model, includes natural order hypothesis in one of his hypotheses. He says that “second language learners seem to acquire the features of the target language in predictable sequences”.
Considering this hypothesis it’s worth investigating the SLA developmental sequences in students’ writing skill in the level of junior or senior high schools. This research becomes important to make the teachers aware that there are some predictable sequences in students’ second language acquisition, so they will not get stressed if they still find some mistakes in the students’ work. The teachers also can expand this research by making the writing syllabus that fits this natural order of second language acquisition.
Of course, in the further research, we can expand it by investigating the development sequences in the acquisition of speaking skill.