Can someone help me please with this gridview formula?

I was successful in this formula:

IF({Tax Group}= " ON",{GST/HST},0)

However, now I want to add if the tax group is ON OR QC.

IF({Tax Group}= " ON",
OR({Tax Group}= " QC",
{GST/HST},0)

But when I do this my evaluation fails. I've tried various ways to add the OR statement but I'm doing something wrong.

Thanks!