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.
نَسِيُوا → نَسُوا Past: they (m.)يَنْسَيُ → يَنْسَى Present: heأَنْسَيُ → أَنْسَى Present: Iيَنْسَيُونَ → يَنْسَوْنَ Present: they (m.)