Here is the simple buttonhole in a 2 by 2 rib that I used on my last sweater and it is easy and looks nice. If you are using the passap the buttonhole stitches are transferred from the front bed to the back bed. On other machines you transfer the ribber stitches to the main bed. In the pictures you will see that the first step is to take the two front bed (ribber ) stitches and transfer them to the back bed(main bed) . Once you have transferred the stitches, leave the empty needles in work position and knit one row. You will see the yarn laying in the two empty front bed(ribber) needles. We all know that if you knit another row, the stitches won’t knit off properly. In the second picture you will take a transfer tool and go between the two needles with the yarn laying in the latches and lift it gently and transfer that loop to the right needle on the back (main) bed .(Make sure the yarn stays in the needles.) Now finish the rest of the rows in the band. I like the way the hole is in the purl side between two knit columns. It came out perfect for the button that I chose.