Grammar JLPT Level N3 - Lesson 5

Another expression that uses the noun ほど 'an extent' in Japanese, is ほど～ない. In the (A) part of a sentence, an extent will be highlighted, before the (B) part of the sentence will use ない to negate that extent, saying that it has not been reached. This phrase can be translated as 'it isn't like (A)', 'it's not to the point of (A)'. Literally it means 'if (A) is the extent, then (B) is not true'.
ほど will regularly be used after a verb or noun, while ない is more likely to be used after a verb, い-Adjective, or な-Adjective (as it is describing something about ほど).

• 今日(きょう)は思(おも)ったほど暑(あつ)くなかった。
  Today wasn't as hot as I expected.
• 悩(なや)むほどの事(こと)じゃない。
  It is nothing to worry about so much. (This is not as serious as you think it is)
• 自転車(じてんしゃ)は車(くるま)程(ほど)速(はや)くないけど、健康(けんこう)にいいから自転車(じてんしゃ)で会社(かいしゃ)に行っ(い)ています。
  Bicycles aren't as fast as cars, but it is good for my health, so I ride my bike to work.
• この世(よ)にこのカレーほど辛(から)い食(た)べ物(もの)はない。
  There is no food as spicy as this curry in the world.

While this grammar point may be used for expressing that an extent has not been reached, it is also frequently used for making comparisons between two things. In these cases, it states that 'the example/limit of (A) is something that cannot be reached/repeated by (B)'. This is similar to '(B) is not as ~ as (A)' in English.

• お母(かあ)さんほどケーキ作(づく)りが上手(じょうず)な人(ひと)はどこにもいない。
  There is no one in this world that is as good as my mom at baking cakes.