An emphatic lām with heavy nūn of emphasis strongly reinforces an imperfect verb. Some pronoun endings are shortened, while feminine plurals need a separating vowel/alif pattern.
PositionHeavy-nūn active
هُوَلَيَقُولَنَّ
هُمَا (م)لَيَقُولَانِّ
هُمْلَيَقُولُنَّ
هِيَلَتَقُولَنَّ
هُمَا (ف)لَتَقُولَانِّ
هُنَّلَيَقُلْنَانِّ
أَنْتَلَتَقُولَنَّ
أَنْتُمَا (م)لَتَقُولَانِّ
أَنْتُمْلَتَقُولُنَّ
أَنْتِلَتَقُولِنَّ
أَنْتُمَا (ف)لَتَقُولَانِّ
أَنْتُنَّلَتَقُلْنَانِّ
أَنَالَأَقُولَنَّ
نَحْنُلَنَقُولَنَّ
لَيَقُولَنَّ — he will certainly say.
لَتَقُولِنَّ — you (feminine singular) will certainly say.
Simply appending a nūn to every unaltered indicative form does not yield the correct paradigm.