Find the mistake

yesterday ,I could lift the heavy bag by myself
وهنا يكون الخطأ فى could
والأجابة تكون
was able to او managed to

```````````````````````````````````````````

I was able to swim when I was 5 years old
الخطأ يكون فى was able to
والأجابة تكون could

`````````````````````````````````````````````````` `
تستخدم could فى الماضى للتعبير عن مقدرة فعل ما بشكل عام مثال الجملة الثانية
وتستخدم was able to , managed to فى الماضى للتعبير عن مقدرة فعل ما فى مرة واحده فقط وليس بشكل عام مثال الجملة الاولى

`````````````````````````````````````````````````

لاحظ اننا يمكننا ان نستخدم couldn't للتعبير عن عدم القدرة بشكل عام او مرة واحده فى الماضى
اى يمكننا ان نقول
yesterday , I couldn't lift the heavy bag by myself

حفظك الله ورعاك اخى الفاضل

حفظك الله ورعاك اخى الفاضل

جزاك الله خيرا