Establishing the Standards and Categories in Distinguishing Diacritics from Letters in Arabic and English

A diacritical mark is a mark which is put above or below the letter. That is to say, diacritical marks are seeming letters that play a vital role in attributing words to different classes. According, they can change the syntactic function as well as the part of speech of the words they are used with. Thus, they are dealt with by different fields of linguistics, such as phonetics, syntax, and so forth. However, the current study aims at investigating the importance of these marks in English and Arabic to show how important these marks are and how similar universally each language with the other(s). In addition, the study comes against the long-adopted view of the importance of these marks in language.