I'm Stuck on Shaping Armhole!

I haven’t knit in over 30 years but decided to knit my new grandchild a little sweater set. Everything seemed to be going fine until I hit the ‘Shape Armhole’ section of the pattern… and I just don’t get what I’m supposed to do. The instructions say,
“[B]Next Row:[/B] Cast off 3 sts in patt, patt to end [39 sts]” (okay, no problem yet)
“[B]Next Row:[/B] Sl 1, k4, patt to end”
“Work 11 rows dec 1 st at armhole edge in next and every foll alt row [33 sts]”
“[B]Next Row:[/B] Sl 1, k4, p2, (p 2 tog) 12 times, p2 [21 sts]” Leave 21 sts on a holder.

When it says “Work 11 rows…” it doesn’t say whether you’re supposed to maintain the pattern, or what? If so, why wouldn’t it say “in patt” as it has previously throughout the instructions?
Perhaps for clarification I should mention that these four rows form the basic pattern:
[B]1st row: [/B]K1, *yrn, p1, p3tog, p1, yon, k1, rep from * to last 5 sts, k5
[B]2nd row:[/B] Sl1, k1, purl to end
[B]3rd row:[/B] Knit
[B]4th row:[/B] Sl1, k1, purl to end
Immediately before starting the “Shape Armhole” instructions it said to “end with a 2nd row”, which I did. Therefore, according to my interpretation, the first row of the “Shape armhole” (after casting off 3) was a plain “knit to the end” row and the second was a “Sl1, k4, purl to the end”.

I hope this makes sense and I haven’t confused everyone else as thoroughly as I am. [B]ANY [/B]advice would be [I]very [/I]much appreciated!

Can you look at the picture of the sweater and tell if it continues in pattern on the upper portion of the front?

Despite the fact that it doesn’t tell you to continue the 11 rows in pattern, I’m guessing that that’s what you should do. That means that every other row you’ll decrease one st at the armhole edge. The next decrease will be on a row 1 and it will interrupt the pattern. That’s ok but because the pattern repeat has 2 increases (the yrn’s) and 2 decreases (the p3tog) I think you should switch to all knit st for this first pattern repeat and then continue the pattern with the next repeat. Eventually, all these knit sts which are replacing the first repeat will be decreased anyway.

Thank you Salmonmac! I will do as you’ve suggested and I think I’ll be on the right path. :cheering: