How to Read Crochet Diagrams
Diagrams are read exactly as the crochet is worked. Each stitch is represented by a symbol that has been drawn to resemble its crocheted equivalent. The position of the symbol shows where the stitch should be placed and worked.
Stitch symbols are drawn and laid out as realistically as possible, but there are times when they have to be distorted for the sake of clarity. For example, stitches may look extra long to show clearly where they are to be placed, but you should not try to match the chart by making elongated stitches. Crochet each stitch as you normally would.
The number of strokes crossing the stems of stitches longer than a half double crochet represents the number of times the yarn is wrapped over the hook before the hook is inserted into the work.
Right Side and Wrong Side Rows
Where the work is turned after each row, only alternate rows are worked with the right side of the work facing. These "right side rows" are printed in black on stitch diagrams and read from right to left. Wrong side rows are printed in a different color (usually blue) and read from left to right. Row numbers are shown at the side of the diagrams at the beginning of the row.
Patterns worked in rounds have right side rows facing on every round — alternate rounds are printed in blue and black.
Diagram source: Craft Yarn Council's Yarn Standards.
Download the Sidewalk Shawl pattern to see a written pattern and its matching diagram, then use the video below if you need any help understanding it.