Some letters are used more frequently than others in word construction.

More Frequent		���� ������
Less Frequent		��� ������
Rare		���� �������

Any Arabic word of three letters or more must contain at least one of these six letters: , otherwise the word is not considered Arabic word.

No two letters of the following set can exist together in any Arabic word.

Some letters (like ) are not preceded by other letters (like ) in the word

Some letters (like ) are not followed by other letters (like ) in the word.