Past subjunctive or imperfect?
How would you translate the following sentence?
If he wanted to go, he could have.
Si él quería ir, podía.
Si él quisiera ir, podía.
Is it up to the discretion of the speaker in this case? As in whether or not the speaker believed that he actually wanted to go?
Also, should I have been using some form of "haber" in there to make it more grammatically correct? Si él quería ir, ha podido. ..?
If he (had) wanted to go, he could have (gone)
In English you skip the verb at the end, no can do in Spanish.
Si hubiera querido ir, podría haber ido/habría ido/hubiera ido
Conditional type 2
If he wanted to go, he could go
(Si quisiera ir, podría ir)
It means the same as "he would go if he wanted".
Everything depends if he wants or not to go.
I don't understand what you put about "have".
This verb "wanted" can have two meanings: the normal meaning would be "quería", but as it is a conditional, a lot of conditionals in past are expressed as "subjunctive". In this case, the meaning of "wanted" is "quisiera or quisiese".
I am sorry to say that I cannot inform you a lot about subjunctive, but there are some people who perhaps could do it. The best thing is that you look for information about subjunctive in Spanish.
Here you have a link about a Spanish verb. It can be used as a reference.