• The harder he tried, the further he fell behind.
• The older the children are, the more their parents expect from them.

The first example contains the two parallel comparatives, “the harder” and “the further”: The second example contains the two parallel comparatives, “the older” and “the more”.

In this type of sentence, the and the comparison can be followed by a number of different structures.

• The more children you have, the bigger the house you need.
• The harder you work, the more you accomplish.
• The greater the experience, the higher the salary.

In the first example, “the more” is followed by the noun “children” and the subject and verb “you have”, while “the bigger” is followed by the noun “the house” and the subject and verb “you need”. In the second example, “the harder” is followed by "the subject and verb “you work”, while “the more” is followed by the subject and verb “you accomplish”. In the third example, “the greater” is followed only by the noun “the experience”, while “the higher” is followed only by the noun “the salary”. You should note that this last example does not even contain a verb, yet it is a correct structure