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.
بَكَيَ → بَكَى Past: heبَكَيَتْ → بَكَتْ Past: sheبَكَيُوا → بَكَوْا Past: they (m.)يَبْكِيُ → يَبْكِي Present: he