"كنتُ لَغيّرتُ جوابي."
الترجمة:I would have changed my answer.
Would is usually used in English for conditional statements. In this example there is one part missing. Let me try writing the complete sentence so you can get more context.
If I knew it was wrong, I would have changed my answer. لو عرفت إنه غير صحيح كنت لغيّرت جوابي.
السلام عليكم يا صديقي And congratulations for finishing the course! :D Weeeee! :D بارك الله