Student or Learner
If you had been able to speak English, you might have got the job.
Can I replace had been able to by could?
So, the sentence will be like this:
If you could speak English, you might have got the job.
In that context yes, because if the person could have spoken English at the time of the interview/job application, then they can probably still speak English now. "If you could speak English" is a general reference covering the time of the job application and the present time. You could use:
If you had been able to speak English, you might ...
If you had been able to demonstrate your English skills, you might ...
If you could have spoken English, you might ... (this is more like saying "If you'd been allowed to speak English at the interview" or something similar).
If you could speak English, you might ...
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.