说话小心，行动谨慎to speak and act cautiously

• 美国总统候选人配偶说即使进了白宫，也得谨言慎行。

  The US presidential candidate's spouse said that they must speak and act cautiously, even if they get into the White House.

• 到了新的环境里后，要谨言慎行，和同事们处理好关系。

  After moving to a new environment, one must speak and act cautiously and handle one's relationships with one's colleagues well.