Rule 1: 1. خَيْرٌ مِنْ 'better than'
Better is not formed from طَيِّبٌ good with the pattern أَفْعَلُ; Arabic uses the noun خَيْرٌ good, goodness followed by مِنْ: اَلْعِلْمُ خَيْرٌ مِنَ الْمَالِ knowledge is better than wealth. خَيْرٌ keeps its tanwīn and never changes for gender or number. Its opposite is شَرٌّ مِنْ worse than.
اَلْعِلْمُ خَيْرٌ مِنَ الْمَالِ.
al-ʿilmu khayrun mina-l-māli
Knowledge is better than wealth.
كَلِمَةٌ طَيِّبَةٌ خَيْرٌ مِنْ مَالٍ كَثِيرٍ.
kalimatun ṭayyibatun khayrun min mālin kathīrin
A kind word is better than much wealth.
خَيْرٌ does not become feminine.
هٰذَا الدَّفْتَرُ خَيْرٌ مِنْ ذٰلِكَ الدَّفْتَرِ.
hādhā-d-daftaru khayrun min dhālika-d-daftari
This notebook is better than that notebook.
صَدِيقٌ جَاهِلٌ شَرٌّ مِنْ عَدُوٍّ عَاقِلٍ.
ṣadīqun jāhilun sharrun min ʿaduwwin ʿāqilin
An ignorant friend is worse than a wise enemy.