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.
أَنْهَيَ → أَنْهَى Past: heأَنْهَيَتْ → أَنْهَتْ Past: sheأَنْهَيُوا → أَنْهَوْا Past: they (m.)يُنْهِيُ → يُنْهِي Present: he