Help with Scarf!

Hi Everyone! I am trying to knit this scarf for my mom and have run into some confusion! What is the difference b/w SL1 and PSSO?? I have looked everywhere on the internet and cannot find much about PSSO. And last question, what does it mean on Row 2 & 4 (WS)…Do I flip the needles or witch hands or just continue doing what I’m doing?? Thank you for any help!!! I posted the instructions below as well as the link.
http://www.jimmybeanswool.com/freeKnittingPatternTaoSilkScarf.asp
Finished Measurements: 6 1/2 x 86 inches

Materials
1 ball of Colinette Parisienne in 163 Vincent’s Apron
2 balls of Colinette Tao Silk in 163 Vincent’s Apron
Straight knitting needles, US size 9
Gauge
Not super important…

Abbreviations
rs: Right Side
ws: Wrong Side
K: knit
P: purl
K2TOG: knit 2 stitches together, as if they were one.
PSSO: pass slipped stitch over.
YO: yarn-over

Directions:
Holding 1 strand each of the Tao Silk and the Parisienne together, CO 28 sts

Row 1(rs): K2, *K3, YO, SL 1, K2TOG, PSSO, YO; repeat from * to last 2 sts, K2
Row 2 & 4 (ws): Purl
Row 3: K2, *YO, SL 1, K2TOG, PSSO, YO, K3; repeat from * to last 2 sts, K2
Repeat rows 1-4 until scarf measures about 85 inches unblocked (or until you only have enough yarn for 1 more row). BO all stitches.

Slip one means to pass the stitch unworked from the left needle to the right needle. PSSO means to pass slipped stitch over. So in this case (and this is a very common combination of procedures) you would slip one st from the left to the right needle, knit the next 2sts together and then take the slipped st which is sitting on the right needle, bring it over the st on the right needle nearest the tip of the needle (the st formed by the k2tog) and let it drop off the right needle. You’ll be decreasing 2sts (but increasing 2sts with the YO’s).
For the even number nows which are the wrong side, just switch the needle from your right hand to your left hand when you come to the end of the previous row and work across the even row in purl.
Best not to give the entire pattern, just the relevant rows due to copyright issues.

Thank you so much for the help! I have now encountered yet another problem! For some reason my stitches have steadily decreased from CO 28 to 21 to now 18! I was so excited bc I thought I had he hang of it and now I’ve somehow screwed up again:( Any ideas as to how I can fix this without starting over!

Look at your sts and see if you are doing the yarn overs. It’s easy to forget them or let them slip off the needle. You can recognize them because they will create a hole wherever you have one. If you need to see a yo, look under yo in the Glossary tab at the top of the page.

The sl and psso are not separate, there’s a k1 or k2tog between them and it’s all part of a decrease. That’s why you have less stitches, but the YOs offset them and every sl k2tog, psso has a yo before and after it. So see if you’re doing them right, just wrap the yarn around the needle as if doing a knit st except the R needle isn’t in a st on the L needle.

Also, when you are working on Rows 2 & 4, you are supposed to Purl all the stitches for those rows. (even the yo’s from the rows before). Each yo from the previous row “counts” as a new stitch that you will purl.

So, it goes like this:

Row 1 - Do the stitches it says to
Row 2 - Purl all the stitches on this row
Row 3 - Do whatever it says
Row 4 - Purl all these stitches

The “ws” means that row is the “wrong side” of the scarf.

HTH, knitcindy