Our school is having a debate over a student's answer to a test.
"The higher we go up, the colder weather becomes."
Is the "the" necessary between colder and weather? Why or why not?
I would say the colder the weather becomes.
1. We go up higher and the weather becomes colder.
This is OK, but it does not mean exactly the same as
2. The higher we go up, the colder the weather becomes.
#1 simply records two situations: We go up higher. It becomes colder. The two are not necessarily related.
#2 tells us that the weather becomes increasingly colder as we go higher. The fall in temperature is related to our ascent.
NOT A TEACHER
(1) "The warmer the weather, the better I feel." (Murphy, Raymond. Grammar in Use.)
(2) Your sentence should -- in my opinion -- read:
The higher we go up, the colder the weather becomes.
(a) The first two the's are adverbs that = by that much.
(b) the third the is just the regular definite article. (In my opinion)
(c) By that much higher we go, by that much colder the weather becomes.
Swan, Michael. Practical English Usage.
Pence R.W. and Emery D.W. A Grammar of Present-Day English.
House, Homer C. and Harman, Susan Emolyn. Descriptive English Grammar.