the.com/behalf

The invisible permission slip that lets you speak as if you were someone else.

means Acting or speaking on someone's behalf means doing it in their place, with their interest or authority standing in for your own.

from Built from the Old English phrase 'be healfe,' meaning 'by the side of' — healf being the same root that gives us 'half,' originally meaning 'side.' So to act on someone's behalf is, quite literally, to stand at their side, lending them yours.

origin
blend of by and half, meaning on someone's side
usage trap
on behalf of means representing, not just for
grammar tell
always needs a someone, never stands alone
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