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.
سَعَيَ → سَعَى Past: heسَعَيَتْ → سَعَتْ Past: sheسَعَيُوا → سَعَوْا Past: they (m.)يَسْعَيُ → يَسْعَى Present: he