Pattern question

Hello, I am working on a wonderful cotton tank (for someone leaving for Brasil). I am working on the straps and I need help figuring out when to decrease. The pattern is as follows:

dec 1 st each neck edge on next RS row as foll: blah, blah, blah, I get this part. Rep this dec row on [B]alt 2nd and 4th rows[/B] 11 times until straps on each side of the neck have 12 sts.
I just finished the first decrease row…I know that I should only decrease on RS rows - but which ones? I need an interpretation!!
Can someone please spell it out for me?!

“alt 2nd and 4th rows” would be dec on the 2nd row after the 1st dec row, then the 4th row after that, then the 2nd row after that, then the 4th row after that, etc… That’s to avoid a dec on the WS row which would be something like every 3rd row. Which you could do instead.

thanks! why can’t they just say: decrease on every RS row until there are 11 sts left? Wouldn’t that have been easier?

Because it’s not decrease on every right side row, you alternate decreasing on every 2nd [B]and[/B] 4th rows.

Your first dec row we’ll call row 1, then dec on Rows 3, 7, 9, 13, 15, 19, 21, etc.