We must acquire proficiency in defense and display stamina in purpose.

To acquire proficiency in the Manual of Arms, you should practice, practice, and practice.

But if we don't practise on some one, how are we to acquire proficiency?

Deep-sea divers only acquire proficiency after long training.

The board's intention, they now said, was to make sure black children acquire proficiency in standard English language skills.

The word implies more than acquired proficiency, a natural inborn aptitude.

These are quickly and easily prepared and, after a few trials, one acquires proficiency.