The process of syllabus design in foreign language teaching mainly includes selecting and grading what is to be taught. A process of selection must be undertaken since learning the whole system of a foreign language is neither possible nor necessary. Selection involves two sub-processes. First, the restriction of the language to a particular dialect and register of the items that are to be taught according to criteria such as frequency of occurrence, learnability and classroom needs. The whole process of selection must be applied at all levels of language, such as phonology, grammar, lexis, contexts (semantic and cultural). After a list of language items have been selected, the next process is to put them into the most appropriate order for practical teaching purposes. This process is often referred to as grading or sequencing.