to some purpose—effectively; with good result:
- The merchants could concert together for the saving of their credit: and they did it to some purpose.
to the purpose—pertinent to the matter or subject in question:
- John never wastes time; he speaks plainly and to the purpose.
Note: The expression does not correlate in meaning with the phrase on purpose—intentionally; not by chance:
- It wasn’t an accident—he broke the window on purpose.