The sound and pronunciation of a word is very important in Arabic, and this especially becomes a problem in the case of generating new words via the naht process. (Although it was mentioned before that one cannot do naht at their whim, the council of Arabic Language has permitted cases of naht to be submitted to them for review for the sake of meeting with the demands of modern terminology into the language).
Some of these problems are that when you combine two or more words in naht, some of the letters invariably have to be dropped. But which letters are dropped and which are retained is a crucial issue, for there are a number of linguistic ‘flaws’ related to words, some of which are that two letters following each other may be considered heavy on the tongue (al-thiqal), or adjacent letters may be discordant or inharmonious with one another. Thus, Ibrahim Anees offered some guidelines (published in Mujallat Majma’ al-Lughah al-‘Arabiyyah fee al-Qahirah, ed. 30) followed by classical scholars in the words they welcomed into the language, to help us judge whether new words are harmonious and acceptable to Arabic or not. Some of these are:
1. The letters Taa’ ط and jeem ج are not found in the same word.
2. The letters jeem ج and Saad ص are not found in the same word.
3. The letters Saad ص and Taa’ ط are not found in the same word.
4. The letters seen س and dhaal ذ are not found in the same word.
5. The letters seen س and zaa’ ز are not found in the same word.
6. The letters qaaf ق and jeem ج are not found in the same word.
7. The letter zaa’ ز will not come after the letter daal د in the same word.
8. The letter raa’ ن will not come after the letter noon ن in the same word.
9. Any word from a root of four or five letters must have at least one (sometimes two or three) liquid letters حروف الذلاقة (ie raa’, laam, noon, faa’, baaa’ and meem ر ل م ن ف ب)
In addition to helping us judge the quality of a word, these guidelines also serve to provide much fun in trying to find those ‘there MUST be some!’ words that prove this wrong. I was unable to think of any, but would welcome anyone else’s successes.