I’ve heard these two adverbs confused twice this week, so I decided it would be worth looking closely at their definitions:

Purposely means intentionally, deliberately, on purpose.  When you mean to do something, you do it purposely:

• She crossed the road purposely because she didn’t want to have to speak to her ex-boyfriend.
• The footballer purposely tripped up the goalkeeper so that the ball would go into the net.

Purposefully means with a strong sense of purpose, or with determination and intent.  When you are determined to do something, you do it purposefully.

• She purposefully set about writing a full account of what had happened while it was fresh in her mind.
• Determined not to get involved in the fight, he walked purposefully in the opposite direction.