The light emphatic nūn is sākin and lacks a shaddah. It can reinforce imperatives too, but the original chart leaves six light-nūn positions empty: both third-person duals, both second-person duals, and both feminine plurals.
Word / formMeaning / explanation
اِفْعَلَنْcertainly do (masculine singular).
لِيَفْعَلَنْlet him certainly do.
اِفْعَلَانِّyou two must certainly do (heavy nūn); the corresponding light-nūn entry is absent.
Hence each heavy-nūn paradigm covers fourteen positions while the light-nūn counterpart covers only eight listed positions.