difference between blunt and brusque

Solution 1:

He spoke brusquely/bluntly.

Brusquely describes how you deliver your comment (abruptly, tersely, briskly, peremptorily, offhandedly, rudely ...(OED))

antonym - politely, verbosely (Google)

Bluntly describes the character of your comment (without ceremony or delicacy; abrupt, curt, to the point, frank, candid, direct, bluff, undiplomatic, indelicate, ...(OED))

antonym - subtly, tactfully (Google)