Learning to speak and understand a foreign language like a native is a long process. It's not enough to know how to express any idea, you have to speak idiomatically. Native speakers use idioms all the time. These can be learned from a dictionary. But they also use figures of speech and that takes more time to learn.

After some time of careful study you'll understand such idiomatic and figurative expressions better. Then you'll begin to use them yourself.

Here is an example of the difference between highly idiomatic, with slang and figures of speech and plain vanilla, candid English.

Kojak Season I, episode "Dead on his feet" Listen MP3 file (391 Kb) Kojak is briefing his squad of NYPD detectives after the killing of a cop. I know the slang used by Kojak is old fashioned and you may find my 'candid' translation too candid, but that's not the point.
Original dialog		Candid translation
I want them to pick up the tab for a change.		I want the criminals to pay the price for a change.
I want them to know we don't come cheap. And how're gonna do that? Pressure!		I want them to know that [killing a police officer] will cost them dearly. And how are we going to achieve that? By applying pressure!
You're gonna pressure every pimp, every shylock, every bookie, every foot soldier, every hit man, every street walker.		You are going to pressure every procurer of prostitutes, every usurer, every [illegal] bookmaker, every junior member of a crime syndicate, every contract killer, every prostitute who sollicits on the street.
They sneeze in the subway, bust their chops. If they ask you for the time of day, you lock them up.		You will arrest them for the slightest offence.
Let the word go out loud and clear: That's the way it's gonna be until Eddie Ryan's killer's in the Tombs.		Get the message to to them : we will harrass them until the killer of Detective Eddie Ryan is in prison.

On the left is the original Kojak dialog. On the right is a litteral, candid translation of what he is saying, or how a non-native English speaker with basic fluency might try to say it.

Could you understand Kojak in your target language? Can you speak like Kojak?