Common mistakes
The middle radical is و or ي. It stretches into a long vowel: قَالَ: and shortens before a consonant ending and in the jussive: قُلْتُ, لَمْ يَقُلْ.
كَوَنَ → كَانَ Past: heكَوَنَتْ → كَانَتْ Past: sheكَوَنْتَ → كُنْتَ Past: you (m.)كَوَنْتُ → كُنْتُ Past: I