What it means
ほど〇〇ない expresses that something does not reach the same degree, amount, or level as a person or thing used before ほど. It is commonly translated as “not as ... as.” The comparison target comes before ほど, and the following predicate is negative. The predicate can describe size, difficulty, speed, ability, frequency, or another measurable quality.
Usage note
With an adjective predicate, use the negative form appropriate to the register: ～くない in familiar speech and ～くありません in polite speech. This pattern is different from ～ほどではない, which more broadly means that something is not to the extent of a stated standard.
How to use it
この町は東京ほど大きくありません。
This town is not as large as Tokyo.
予想したほど難しくありません。
It is not as difficult as I expected.
この町は東京ほど大きくない。
This town is not as large as Tokyo.
予想したほど難しくない。
It is not as difficult as I expected.