Looking on how to improve my essays, I've just come across the idiom 'speaks volumes about'. For example:
The unsightly yard and unpainted house speaks volumes about what kind of people live there.
However, all the examples I've seen use it in kind of informal way. Would it be valid to be included in a formal essay?
PS: One example of a formal use would be writing to your college director to do some proposal to improve building's installations:
The anual asset from the magazine has given an outstanding review of the college, which speaks volumes about it. However…
Best Answer
The idiom speak volumes (about something refers to communication without words, which is why, in your examples, a yard and a house can be said to speak.
(Cambridge)
See also the other definitions and examples given at The Free Dictionary.
Applying the idiom to written communication does not represent natural usage of the idiom.
It does not seem out of place regarding formality in the sentence you wrote. So, yes, the idiom can be used in a formal essay, including "writing to your college director to do some proposal to improve building's installations."