There is a chart below for translating crochet patterns written in British English crochet terms into American English crochet terms. For example, a double crochet in British English is made the same way as a single crochet in American English (it is just called by two different names).
Some antique patterns published in the United States in the late 1800s and early 1900s use British English crochet pattern terms also. In any pattern or publication, there is usually a section giving a description of the way each stitch is made and you can determine by that if the double crochet, for instance, is a British English or an American English double crochet. Then you'll know if that entire publication is written in British or in American English crochet terms.
Translating Crochet Terms Between British and American English
|British vs American English Crochet Patterns||British English||USA - American English|
|double crochet (dc)||single crochet (sc)|
|half treble (htr)||half double crochet (hdc)|
|treble (tr)||double crochet (dc)|
|double treble (dtr)||treble (tr)|
|triple treble (trtr)||double treble (dtr)|
|yarn over hook (yoh)||yarn over (yo)|