What is the ism of ma and la resembling laysa?
In one line
Definition
Key words in the Arabic
Understand it
لَيْسَ is one of the sisters of كَانَ: it raises its noun to rafa and puts its khabar into nasab.
Some uses of مَا and لَا negate in precisely that manner, and the grammarians say they resemble لَيْسَ — مُشَبَّهَتَانِ بِلَيْسَ. When they do, they work as it works.
In مَا زَيْدٌ قَائِمًا (ma zaydun qa'iman), Zayd is not standing, زَيْدٌ is the ism and stays marfu'; قَائِمًا is the khabar and is mansub.
What they do
They copy لَيْسَ exactly: the noun stays in rafa, the khabar drops into nasab.
The two are not interchangeable. مَا may enter upon a definite noun or an indefinite one; لَا is restricted to indefinite nouns alone — لَا رَجُلٌ أَفْضَلُ مِنْكَ (la rajulun afdalu minka), no man is nobler than you.
The resemblance is conditional, not automatic. Break the negation with إِلَّا, or put the khabar before the noun, and مَا stops governing — the sentence returns to being a plain mubtada' and khabar, both marfu'.
Because the conditions are fine and the usage is limited, this role is the least often met of the eight.1
How to spot it
Don't confuse it with la of absolute negation
Do not confuse this لَا with the لَا of absolute negation.
The لَا here resembles لَيْسَ: its noun stays marfu'.
The لَا لِنَفْيِ الْجِنْسِ does the opposite: its noun is mansub, and it carries no tanwin — لَا رَجُلَ فِي الدَّارِ.
Same letter, two different jobs, opposite endings on the word that follows.
Related terms
Common questions
Why is it described by resemblance rather than given its own name?
Because the grammar is borrowed. These particles are not verbs, but under certain conditions they govern exactly as laysa does — the noun in rafa, what is said about it in nasab. The name records where the behaviour came from.
Next in the guideخَبَرُ لَا الَّتِي لِنَفْيِ الْجِنْسِWhat is the khabar of la of absolute negation? →Notes
- It is the seventh of the eight in اَلْهِدَايَة فِي النَّحْو (al-Hidaya fi al-Nahw) — the book that defines these two roles most clearly — and تَسْهِيل النَّحْو (Tasheel al-Nahw) takes its list and its order from there. ↩
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