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.
غَطَّيَ → غَطَّى Past: heغَطَّيَتْ → غَطَّتْ Past: sheغَطَّيُوا → غَطَّوْا Past: they (m.)يُغَطِّيُ → يُغَطِّي Present: he