grammar correction please?

[abcd1234]

I'm not so sure if you are already have MASTERED the REGEX subject to say this.

or

I'm not so sure if you are already had MASTERED the REGEX subject to say this.

Please correct the "already have mastered" or "already had mastered".
Which is the most appropriate?

Thank you very much in advance.

[Humble]

You don't need ARE there.
I am not sure you have already mastered...

[abcd1234]

thanks