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.
اِخْتَيَرَ → اِخْتَارَ Past: heاِخْتَيَرَتْ → اِخْتَارَتْ Past: sheاِخْتَيَرْتَ → اِخْتَرْتَ Past: you (m.)اِخْتَيَرْتُ → اِخْتَرْتُ Past: I