The first source exercise also asks for أَمْنَعُ and أَعْلَمُ. The same eight templates apply, but the root consonants differ.
Word / formMeaning / explanation
أَمْنَعُmore resistant/restraining, root m-n-ʿ.
أَمْنَعَانِ / أَمْنَعُونَ / أَمَانِعُits other masculine slots.
أَعْلَمُmore knowledgeable, root ʿ-l-m.
أَعْلَمَانِ / أَعْلَمُونَ / أَعَالِمُits other masculine slots.
The exercise combines root identification, gender/number and the sense of greater degree. The plural entries are presented as pattern drills, not claims that each is equally idiomatic.