Decreasing stitches on neck edge
I am knitting the front of a sweater which has a turtle neck. I'm about to start shaping the neck.
The pattern says: Rib 14 turn. Cont on these 14 stitches. Dec one st at neck edge in every foll alt row until 11 stitches remain.
I understand what I have to do, the problem is when I am decreasing, I have to keep in the pattern. The rows are either K2, P3 etc, or P2, K3 etc. What do I do when I have a purl and a knit following each other and I have to decrease staying in pattern? As it is a rib, I was trying to keep each line of ribbing continuing up the sweater, but if I do that, then some of the purl in between each set of ribbing, gets less. Is that right?
All help is appreciated. Thanks