Begin with 4 chain stitches, and work 1 single on the 1st chain, to make a round. Work, 1 chain and 2 plain on the next chain, 3 plain on each of the next 3 chain, 1 plain on the stitch on which the two first plain are worked.
Slip the next stitch, that is, put the needle in between the horizontal bars of the 1st plain stitch of the previous row, and draw the thread out without making a stitch.
Then make 1 chain and 2 plain on the slipped stitch.
After which, you make 3 plain on the second of the 3 plain that form the corner, and 1 plain on all the other stitches of the last row. The beginning and end of each row, are worked as described above.
This figure represents a square, worked in consecutive rows. In making a crochet square, the rows may end in the middle of a side.
When you use a stitch that has to be worked to and fro, you turn your work at the end of every row and work back along the stitches you have just made.