This pattern is kind of jersey which is mostly used in machine knitting.
Although making it is as easy as 2 purls and 2 knits instruction, knitting the first stitches may be confusing a little bit.
To catch up the pattern I suggest you to cast on any multiple of 4 stitches and knit at least 10 rows.
There are two main rules at this pattern:
1. Except the first row which is the base row, in all rows instruction is repeat of 2P, 2K.
2. The stitch which comes up as Knit stitch , and the stitch right before that one, will be knitted .
Row 1 ) Knit 3 , Purl 1
Row 2) Pick up the first stitch, then repeat ( 2 Purl, 2 Knit )
Row 3) Pick up the first stitch,
knit the 2nd stitch,
then repeat ( 2 Purl, 2 Knit )
Repeat from row 2