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.
رَضِيُوا → رَضُوا Past: they (m.)يَرْضَيُ → يَرْضَى Present: heأَرْضَيُ → أَرْضَى Present: Iيَرْضَيُونَ → يَرْضَوْنَ Present: they (m.)