You can adopt a child or a custom or a law; in these cases you are making the object of the adoption your own, accepting it. If you adapt something, however, you are changing it.
Ready to adapt to change? The revised and expanded third edition of Common Errors in English Usage is now available for pre-order on the William, James & Company Web site. The cover price is $19, but enter the coupon code FIFTEEN to buy it for the introductory price of $15 through the end of this year.
Read about the new edition on the Common Errors blog.
If you are not ready for a change, you can still order the second edition at the discounted price of $12 (while supplies last).
As always, both editions come with free shipping within the US.