事半功倍的英文：
[Literal Meaning]
do/half/efficiency/multiply
to get twice the result with half the effort

[解释]
指做事有方，因而费力小，收效大。

[Explanation]
to work effectively and efficiently

[例子]
因为我们的预算非常紧张，只能用很少的资金完成这个项目，所以一定要做到事半功倍。

[Example]
Our budget is very tight and only a small amount of funds will be invested into this project, so we must work effectively and efficiently.

Everything must be carefully examined before we act, then twice the result can be accomplished with half the effort.
事情要考虑周详以后再动手，才能够事半功倍。