Exception in Arabic - الْاِسْتِفْنَاءُ

المُسْتَثْنَى المُنْقَطَع (Disjointed Exception): This type of exception refers to when the excepted item isn’t part of the main group or category mentioned.

Example:

وَإِذْ قُلْنَا لِلْمَلَائِكَةِ اسْجُدُوا لِآدَمَ فَسَجَدُوا إِلَّا إِبْلِيسَ 

And We said to the angels, “Bow down to Adam.” They bowed down, except for Satan. (2:34)

In this context, Iblis isn’t part of the angels, hence the disjointed exception. The excepted entity, in this case, is always in the accusative form.

2. المُسْتَثْنَى المُتَّصِلُ (Connected Exception): This pertains to when the exception made is related to the main category or group mentioned.

Example:

 فَشَرِبُوا مِنْهُ إِلَّا قَلِيلًا مِنْهُمْ

But they drank from it, except for a few of them (2:249)

For connected exceptions, the case ending (harakah) of the excepted noun depends on various factors:

If the main sentence (without negation or interrogation) and the particle إِلَّا both precede the excepted noun, it will be in the accusative case.

Example:

كُلُّ شَيْءٍ هَالِكٌ إِلَّا وَجْهَهُ

All things perish, except His presence (28:88)

When the sentence has particles of interrogation or negation before إِلَّا, the excepted noun can either have a fatha or take the e’rab of the main category.

Example: 

وَمَا مُحَمَّدٌ إِلَّا رَسُولٌ

Muhammad is no more than a messenger.  (3:144)

If the main sentence doesn’t mention the general category explicitly and is preceded by interrogation or negation particles, the excepted noun will bear its harakah according to its grammatical case (nominative, accusative, or genitive).

Example:

مَا يَعْلَمُهُمْ إِلَّا قَلِيلٌ

None knows them except a few. (18:22)