Yídàn nǐ mínɡbɑi, jiù huì hěn jiǎndān.
一旦你明白,就会很简单。
It's easy once you know how
 
Notes:
一旦(yídàn): once
(nǐ): you
明白(mínɡbɑi): understand
(jiù): just
(huì): will
(hěn): very
简单(jiǎndān): easy
 
Example:
A:为什么我不明白?
     Wèishénme wǒ  bù mínɡbɑi?
     Why don't I understand?
B:一旦你明白,就会很简单。
     Yídàn nǐ mínɡbɑi, jiù huì hěn jiǎndān.
     It's easy once you know how.
Level: