Use the same two-step reading: identify لَمْ, then inspect the following ending.
● لَمْ يَلِدْ وَلَمْ يُولَدْ — both verbs end in sukun; the statement is negative in the past.
● أَلَمْ تَعْلَمْ أَنَّ اللَّهَ عَلَى كُلِّ شَيْءٍ قَدِيرٌ — interrogative hamzah precedes لَمْ; تَعْلَمْ ends in sukun.
● أَلَمْ يَعْلَمُوا أَنَّ اللَّهَ هُوَ يَقْبَلُ التَّوْبَةَ عَنْ عِبَادِهِ — the first imperfect after لَمْ is the second-group form يَعْلَمُوا, whose inflectional nūn has been removed; the later يَقْبَلُ belongs to the clause after أَنَّ.