In Italian, when somebody speaks using words that are too erudite, too formal, or too complicated for the context, we say "parla come mangi" (literally, "speak as you eat").
What phrase should I use in English which is understood to have a similar meaning?
Imagine you ask somebody how to do something, and that person gives an answer that uses too technical words when the answer could simply be "click the red button." Which expression could a third person use to who answered to say "use a simpler vocabulary"?
If there are any difference between American English, and British English, I am interested in hearing them.