Crochet patterns have their own special shorthand that can be intimidating to beginners, but it is easy to figure out once you know the rules. First, almost all the crochet terminology is abbreviated to save space. The abbreviations used are usually listed at the end of the pattern, but some common ones are ch (chain), sc (single crochet), and dc (double crochet).
Ch 12 = chain 12.
Second, crochet pattern directions are written by the row or round, since crochet is always worked either in rows or in rounds. In most patterns, you will be asked to “turn” the work before moving on to the next row. This simply means that you flip the work over so the backside is facing you before moving on. The step ends with the number of stitches you should have once the row or round is completed. For patterns that call for periodic increases and decreases in stitch numbers, it is always a good idea to count your stitches before moving on to the next step.
Row 1. Sc in each ch across. 12 sc.
The last and most confusing part of crochet patterns is the symbols used. Some parts of the instructions may be given in (parentheses) or [brackets]; these are sets of instructions that are either intended to be worked together as one collective stitch, or that are intended to be repeated a given number of times before moving on to the next part of the instructions.
Row 5. Ch 2; turn. (Sc, ch 1, sc) in each ch-1 space across.
Sometimes an asterisk* will appear before certain parts of the pattern. This indicates that the instructions following the asterisk will be repeated within the same row.
Row 10. Ch 2; turn. Skip first sc, *sc in next sc, skip ch-1 space, sc in next sc; repeat from * across.
Once the pattern terminology is broken down, it should be easy to figure out what the pattern is asking you to do. Just take it one stitch, one bracket, one row at a time.
UPDATE: I've received several inquiries about what it means to "work in pattern, "pat across," "work pattern for X rows," etc. To begin, "pat" is an abbreviation for "pattern." The pattern to which the instructions are referring is the stitch pattern that you have been crocheting up until that point. Let's use shell stitch as an example, though this will apply to any stitch pattern:
You have been working in shell stitch for a few rows and the pattern says to "continue pattern for 4 more rows." This means that you should work the next 4 rows in the exact same way that you worked the previous rows (in shell stitch).
You have been working in shell stitch for the first few inches of the row and the pattern says "continue pattern across." This means that you should continue doing the shell stitch across the rest of the row.
Another question I frequently get is what does it mean to "work even"? This simply means that no shaping is involved. Each row in the "work even" section should have the exact same number of stitches as the previous row.