The Four Cases in Which the 
Has Tarqeeq
1. If the has a kasrah, as in :
2. If the is saakinah, and a kasrah precedes it, such as:
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3. If the is saakinah, and the letter before it is saakin, and the letter before that has a kasrah. This would occur when stopping, as in the example:
4. If it is saakinah, and a 
saakinah precedes it. The in this case has tarqeeq no matter what kind of vowel precedes the saakinah. This is exemplified in the following words:
(when stopping on these words).
The Cases Where Both Tafkheem and Tarqeeq are Allowed of the
1. If the is saakinah, and it is preceded by a kasrah, and it is followed by a letter of 
group, and this letter has a kasrah. There is only one example of this in the Holy Qur’an, and that is the word 
in verse 63 of surah Ash-Shuraraa’. The two different ways of reading the apply when continuing the reading, not when stopping. When stopping on the word the has tafkheem, according to the eighth case in which the has tafkheem.
2. If the is saakinah and it is preceded by a saakin letter, which is preceded by a kasrah, and the saakin letter which precedes the , is a letter of group. There are two words in the Qur’an that have these circumstances when stopping on them. They are the words
which is in verse 12 of surah Saba’ and the word,
which is in verse 21, and 99, of surah Yusef, and verse 51 of Az-Zukhruf. These two words can be read with tafkheem or tarqeeq of the when stopping on them. When reading these words in continuum with that which comes after, the rule of the letter depends on the vowel on the ; if there is a fat-h or dhammah, the is read with tafkheem, if there is a kasrah, the is read with tarqeeq.
The Letters that Always have Tarqeeq
The rest of the letters in 
group that remain always have tarqeeq. These are all letters of except the alif, the laam of the Glorious name of Allah, and the .