This study explores invented spelling in Arabic. Since spelling in the United Arab Emirates (UAE) is taught through dictation and composition, this study explores and compares spelling inventions that occur in students' writing in each context. Samples of dictation and composition were collected from three sixth grade classrooms taught by UAE teachers. In addition, this study aimed to investigate what sixth grade students in the (UAE) know about Arabic spelling. A number of features were examined to explore the participants' knowledge and use of certain Arabic spelling rules. Spelling inventions were categorized into three linguistic levels for analysis: 1) phonological level, 2) grammatical level, and 3) orthographic level to answer three of the research question. The findings of student's spelling inventions in their compositions were compared to those found in dictation. Interviews were also conducted to supplement written samples, and to study what sixth grade students report that they do when Arabic standard spelling in unknown. In practice, this study will serve Arabic teachers in the Arabic world as a resource in teaching, evaluating, and understanding invented spelling. Students' invented spellings must be seen as opportunities to contribute actively to their own learning. By combining an understanding of invented spelling with formal spelling instruction, teachers will develop more effective spelling instructions. Findings included: sixth grade students' spelling inventions that occurred in dictations reflected the phonological level primarily; writing compositions drew students' attention to meaning making rather than writing every word accurately; students wrote spontaneously and used their knowledge of information, poems, Koran and Hadith in their compositions. When standard spelling in unknown, students reported that they have many strategies to overcome spelling difficulties such as sounding out, asking for help, visualization, etc. However, they do not advise other students who have spelling difficulties to use the same techniques they use in the same order.