speak the same language

Understand one another very well, agree with each other, as in Negotiations went on for days, but finally both sides realized they weren't speaking the same language. This term, alluding to literal understanding of spoken words, dates from the late 1800s.

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.