Common mistakes
The root ends in و or ي, and the endings themselves change. Three patterns cover it: دَعَا يَدْعُو, رَمَى يَرْمِي and نَسِيَ يَنْسَى.
بَنَيَ → بَنَى Past: heبَنَيَتْ → بَنَتْ Past: sheبَنَيُوا → بَنَوْا Past: they (m.)يَبْنِيُ → يَبْنِي Present: he