Let your conversation be always full of grace, seasoned with salt, so that you may know how to answer everyone.
NIV
Let your speech at all times be gracious (pleasant and winsome), seasoned [as it were] with salt, [so that you may never be at a loss] to know how you ought to answer anyone [who puts a question to you].
AMP
Let your speech be alway with grace, seasoned with salt, that ye may know how ye ought to answer every man.
KJV