Textbook chart of basic-triliteral verbal nouns
#PatternTextbook wordVerb classSense
1فَعْلٌقَتْلٌنَصَرَkilling
2فِعْلٌفِسْقٌنَصَرَdisobedience
3فُعْلٌشُكْرٌنَصَرَthanking
4فَعْلَةٌرَحْمَةٌسَمِعَmercy
5فِعْلَةٌكَدِرَةٌسَمِعَbecoming turbid
6فُعْلَةٌنَشْدَةٌنَصَرَseeking a lost item
The first three patterns differ in vowelization, not radical count. A tāʾ marbūṭa marks an additional syllabic element in another pattern.