What distinguishes fāʾidat al-khabar from lāzim al-fāʾidah?

ʿIlm al-Maʿānī: Khabar, Inshāʾ and the Purposes of Reporting

• The first is always nominal, the second verbal
• The first is true and the second only false
• One conveys the claim; the other shows the speaker knows it
• One is khabar and the other inshāʾ