From Longman Dictionary of Contemporary Englishspeak volumes (about/for something)speak volumes (about/for something)EXPRESSif something speaks volumes, it clearly shows the nature of something or the feelings of a person What you wear speaks volumes about you. → speak
Examples from the Corpus
speak volumes (about/for something)• The 8 successful trips so far speak volumes.• Other than the face, hands are the most visible part of one's body and invariably speak volumes about a person.• But the juxtaposition of the two buildings speaks volumes about the rapid disappearance of regional, vernacular, even weirdo architecture.• Your body language will speak volumes about your happy state. 4 Inhibition decreases.• Jack's tone spoke volumes, but Polly was trying not to listen.• The perpetual grin and I-just-won-the-lottery look on his face spoke volumes: The guy was ecstatic.• His grin spoke volumes to the back row.• Often, though, he speaks volumes when he chooses not to speak at all. 