Hello, here some examples: المعلم كان قادرًا على شرح الدرس | The teached was able to explain the lesson. المعلم قادر على شرح الدرس | The teacher is able to explain the lesson. If this doesn't answer your question please tell me. Good luck!

I'm able to climb this mountain=أنا قَادِر على تسلق هذا الجبل