An emphasis word makes an idea bigger, more stressed, emphasized.
Just, so, such and really are emphasis words.
The emphasis word goes before the word or idea you want to stress.
I want you to walk to the car.
I tell you,
"Walk to the car."
But... if I want you to walk to the car, and NOT GET IN, not turn around, or move...
I would say,
"JUST walk to the car..."
The just puts more stress, more attention to the next word, walk. I am telling you to pay attention, listen to the next word in the sentence... and do only the next word.
"If you would just listen"
means the same thing as
"If you would listen"
I really, really really want you to listen... be quiet for a minute and listen... just listen, do nothing else.
You cheated on a test. I say,
"That is unfair."
But I am VERY mad, so I say,
"That is SO unfair" or "That is JUST unfair" or "That is REALLY unfair."
I could say,
"You cheated?! That is just, so... just really... I mean, it is just so really unfair!"
I explain to you that my job is difficult.
I say, "My job is difficult."
But, I do not think you understand.. you are not listening.. you don't believe me.
So I add emphasis words.
"No, really... it is just thatmy job is difficult... it is reallydifficult... it is just thatmy boss is mean... you see, it is just thatI work all day, many hours... my job is so difficult."