[the sentence is:](https://youtu.be/hk1AvFgOsSo?list=PLzqC6UuRoJ88h8pR6CDmW6SjeT1h7MkJj&t=369)

If you **didn't** want to buy that shirt you shouldn't have bought it *('didn't' - it's a past simple not a second conditional, watch the video by the link above)*

Question:

> 
> When can I use a past perfect in the condition part in this sentence *(If you **hadn't wanted** to buy that shirt you shouldn't have bought it)*
> 
> 
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