THE ... THE. COMPARISON.

THE MORE ENGLISH YOU STUDY 

THE FASTER YOU LEARN IT.

Adverb
1. With a comparative or more and a verb phrase, establishes a parallel with one or more other such comparatives.

• The hotter, the better.
• The more I think about it, the weaker it looks.
• The more money donated, the more books purchased and the more happy children.
• It looks weaker and weaker, the more I think about it.

2. With a comparative, and often with for it, indicates a result more like said comparative. This can be negated with none.

• It was a difficult time, but I’m the wiser for it.
• It was a difficult time, and I’m none the wiser for it.
• I'm much the wiser for having had a difficult time like that.

IN BRIEF: That's a standard construction for comparatives: the ... the ...

Each 'the' is followed by a comparative. That example above is the simplest formation and would refer back to something previously said, so many of the words are simply understood. For example, if someone had offered you a piece of cake and wanted to know whether you wanted a big piece or a small piece, you might answer "The bigger (the piece of cake is) the better (I will like it)."

you will also find more complex the... the... sentences:
The longer you wait, the worse it will get.
The more fruit you eat, the healthier you will be.
The less time you waste, the better off you will be.

EXERCISE ONE  EXERCISE TWO