Cách sử dụng
The expression "look a gift horse in the mouth" means to be ungrateful or suspicious of a gift that you have received. It comes from the practice of examining the teeth of a horse to determine its age and health before buying it. When someone gives you a gift, it's impolite to examine it closely for flaws or shortcomings. Instead, you should appreciate the gift and be thankful for the generosity of the giver. So, if someone gives you a gift, don't be ungrateful or suspicious, just accept it with gratitude.