Inc and dec on purl side

Hi there…hope someone can help me with this question. Just wondering if when I’m decreasing (to make a collar) on the purl side, can I still decrease using a sl, sl, knit stitch? Or do I change the knit stitch to a purl stitch since I’m on the purl side? I’m thinking that I don’t, but not sure. I need a left slanting stitch for the side I’m on right now, and I’m confused…

Thanks!

If you ssk, you’ll get a purl bump on the back. You can ssp and that won’t be an issue.