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.
بَيَعَ → بَاعَ Past: heبَيَعَتْ → بَاعَتْ Past: sheبَيَعْتَ → بِعْتَ Past: you (m.)بَيَعْتُ → بِعْتُ Past: I