How to use なるべく

Whoahhh,, take it easy horse-head

So, なるべく comes from the verb 成る(to make something happen, to allow something to happen) and the auxiliary verb べし(has aspects of order, reasoning, obligations, possibility)

and is used when you want to translate feelings of wanting someone to do something if possible. 

So, it's commonly used in daily life and something you will encounter on regular basis. 

Now, this is similar to できたら which translates to " if it's possible/if possible " but なるべく 　is much stronger and often a request you want to push on to someone.

If できたら was a gentle push, なるべく would be a stronger push. 

Sometimes なるべく is also used when one is irritated by a repetitous movement someone does in work environments, daily life and so on.  

Let's go through some examples, 

• 包丁はなるべくまな板の上で使いなさい！！

ほうちょうはなるべくまないたのうえでつかいなさい！！

Make sure(if possible) you use the knife on the cutting board!!

So, I used to cut potatoes and apples without using the chopping board and got scolded several times by my Mom. 

Here なるべく doesn't necessarily have the meaning of " if possible ", it's more like a must. But since my Mom doesn't want to sound like an 鬼（おに、demon）、she's being a lot more charming using なるべく

• A4 サイズの紙はなるべくこっち側に寄せてね。

A4さいずのかみはなるべくこっちがわによせてね。

If possible, try and keep the A4 paper to this side. 

So, in a work environment, we have a new employee who isn't pretty good with using the printers. His work-mate lets him know that A4 papers should be kept at a certain side. 

• ゴミをなるべく燃やせるゴミと燃やせないゴミに分けてね。

ごみをなるべくもやせるごみともやせないごみにわけてね

Try and seperate the garbage into " combustible " and " non-combustible " if possible. 

I guess this is just simply letting one know that garbage is divided into two different categories. 

Not much emotion involved, very neutral.