1. "You can't have your cake and eat it too"
2. "you can't have it both ways"
3. "you can't have the best of both worlds."
To have one's cake and eat it too is a popular English idiomatic proverb or figure of speech, sometimes stated as eat one's cake and have it too or simply have one's cake and eat it. This is most often used negatively, to connote the idea of consuming a thing whilst managing to preserve it. It may also indicate having or wanting more than one can handle or deserve, or trying to have two incompatible things. The proverb's meaning is similar to the phrases, "you can't have it both ways" and "you can't have the best of both worlds."
而下面的幾個，雖然也有人使用，但是在標準英語詞典中卻查不到：
You can not sell the cow and drink the milk.
所以請適當斟酌使用。