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.
نَجَوَ → نَجَا Past: heنَجَوَتْ → نَجَتْ Past: sheنَجَوُوا → نَجَوْا Past: they (m.)يَنْجُوُ → يَنْجُو Present: he