Question:

I was reviewing old chapters and have a question about غير منصرف Ghayr Munsarif words. What would the dual and plural forms take a ن ending? For example, would the dual be كسلان / كسلين. And the plural would be كسلون or كسلين?
Answer:

That’s a great question. You are correct in saying it is غير منصرف ghayr munsarif. In this case we should go to Hans Wehr and see what the dictionary says:

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Plurals
Your steps:
1. Search under the root letter كسل.
2. Find كسلان (highlighted)
3. Then look to the right until you see “pl.”
4. These are all the possible plural forms (كَسالى كُسالِي، كَسْلَى)
Once you are able to find the plurals, you need to ask what kind of plurals these are. In these cases they are جمع التكسير broken because they don’t match the مفرد singular form.
Duals
As for the dual we take the same approach and add the additional ن. So you would end up with:
كَسْلَانَان – state of رفع
كَسْلَانَيْن – state of نصب/جر