Using the same verb shows the distinction between the earlier lā and this lesson's lan and lam.
Word / formMeaning / explanation
لَا يَكْتُبُhe does not write (or, contextually, will not write).
لَنْ يَكْتُبَhe will not write; future negative with final fatḥa.
لَمْ يَكْتُبْhe did not write; past negative with final sukūn.
لَا يَكْتُبُونَthey do not write.
لَنْ يَكْتُبُوا / لَمْ يَكْتُبُواboth lose the nūn, but the first denies future action and the second denies past action.
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Negating the Imperfect with Lan and Lam: Subjunctive, Jussive and Full Paradigms
Using the same verb shows the distinction between the earlier lā and this lesson's lan and lam.
Word / formMeaning / explanation
لَا يَكْتُبُhe does not write (or, contextually, will not write).
لَنْ يَكْتُبَhe will not write; future negative with final fatḥa.
لَمْ يَكْتُبْhe did not write; past negative with final sukūn.
لَا يَكْتُبُونَthey do not write.
لَنْ يَكْتُبُوا / لَمْ يَكْتُبُواboth lose the nūn, but the first denies future action and the second denies past action.