Pattern Help Please!

I am knitting my first sweater(oh boy) and its a baby sweater for my first niece/nephew (awww) anyway I am almost done with the back and am shaping the neck now (I think) but I don’t get the directions. I have Already cast off the middle 18 stitches so I have two columns of 24 stitches each. Now heres the problem… the next row doesn’t make sense.
Pattern:
Shape Neck; WS facing patt 24, cast off 18sts, patt 24. (I’ve done this row)
On 24 sts, dec neck edge on next two rows. Cast off (what does this mean?)
I understand that its saying to decrease on the next two rows but how do I decrease and by how much? If anyone knows or can help please let me know! Thank you soooo much.

Cast off is the same as bind off, you’ll do X sts at the neck edge, it should say. Maybe it just means to dec by 1 st, as in p2tog or k2tog. Do you have a link for the pattern, or can you type out word for word the neck shaping part? You’ll need 2 ends of yarn, btw, one for each shoulder.

That was direct from the pattern but I’ll post it again because it continued:
Pattern:
Shape Neck; WS facing patt 24, cast off 18sts, patt 24.
On 24 sts, dec neck edge on next two rows. Cast off.
Rejoin yarn to remaining sts and work to match.

That is all the pattern says and now that I’ve done the back I realize that it isn’t the clearest pattern in the world but all the other problems I have been able to figure out except this one…
Oh I copied this pattern from a book and don’t have the book right now so could it possible say in the back of the book or some where else?

I think they just want you to dec (some patterns use cast off instead of decrease) a stitch at the neck edge. It gives a little bit of shaping for the neck, just a smidge more than if it was straigth across.

Just to clarify do you mean dec as in k2g every stitch or just one dec on the neck side. If I start out with 24 stiches and dec two rows should I end up with 22sts?

Just a k2tog at the neck edge only. You didn’t say if this is the back or a front you’re doing…

Its the back of the sweater. But the front say to do it too except it says
Pattern:
"Dec neck edge on next 6 rows(22)sts"
So since on the front you have 28 stitches before you start the decrease that would mean you would just k2g on the neck edge. Okay this is finally making sense to me! Thank you so much!

Yep, sometimes you can get a clue from another part of the pattern that might be more clear. You’re going to wind up with 22 sts on each side of each shoulder to seam together.