Recall the Baseline: Laysa

Ism of Mā and Lā Resembling Laysa; Khabar of Lā of Generic Negation

لَيْسَ زَيْدٌ قَائِمًا
Translation: Zayd is not standing.
لَيْسَ: incomplete past-form verb expressing negation.
زَيْدٌ: nominative ism of laysa (ḍamma).
قَائِمًا: accusative khabar of laysa (fatḥa).

Here mā and lā are particles, not verbs, but in the specified constructions they govern the same case pattern.