Know-it-all :
A person who thinks that they know much more than other people.
合成名词 “know-it-all” 带有贬义，意思是 “自以为无所不知的人”，用来形容某人觉得自己比别人懂得都多，其实不然。
例句
Alex is such a know-it-all – he always immediately shouts out the answer in class.
亚力克斯真是自以为什么都懂，他在课堂上总是立刻就喊出问题的答案。
Don’t be a know-it-all – you don’t always get things right.
不要做一个自以为无所不知的人，你并不是事事都对。
Dad is such a know-it-all when it comes to directions – but despite his instructions, we often get lost!
每当要确认方向时，爸爸就自以为什么都清楚，但就算按照他的指示，我们还是经常迷路！
