El que mucho promete, poco cumple

Spanish: &#039;No confíes tanto en Juan. Ya sabes lo que dicen: el que mucho promete, poco cumple.&#039;
English: &#039;Don&#039;t trust Juan too much. You know what they say: he who promises a lot, delivers little.&#039;

This phrase translates to 'He who promises a lot, delivers little.' It is often used to express skepticism towards someone who makes grand promises but rarely follows through.