لَنْ gives the imperfect a strong negative meaning tied to the future.
Compare:
● يَفْعَلُ — He does, or he will do.
● لَنْ يَفْعَلَ — He will not do it at all.
Two things happened together: the meaning became a strong future negation, and the first-group final dammah changed to fatḥah.
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لَنْ gives the imperfect a strong negative meaning tied to the future.
Compare:
● يَفْعَلُ — He does, or he will do.
● لَنْ يَفْعَلَ — He will not do it at all.
Two things happened together: the meaning became a strong future negation, and the first-group final dammah changed to fatḥah.