〜ほど〜ない
Not as… as…machine translation
FormationA は + B (noun/verb plain form) + ほど + adjective/verb in the negative
A は B ほど〜ない means "A is not as… as B": 今年は去年ほど暑くない (this year isn't as hot as last year). The second part is always in the NEGATIVE — that's the telltale sign of this pattern.
A common mix-up: affirmative comparisons use より (去年は今年より暑かったです — last year was hotter than this year), while ほど is used only in negative sentences. Saying 今年は去年ほど暑いです is grammatically wrong.
Before ほど you can also have a verb in the dictionary form or た-form: 思ったほど難しくない (not as hard as I thought), 言うほど簡単じゃない (not as easy as people say). The chunk 思ったほど〜ない is extremely common — well worth memorizing as a single unit.
Examples
今年の夏は去年ほど暑くないです。
This summer isn't as hot as last year.
私は兄ほど背が高くないです。
I'm not as tall as my older brother.
漢字は思ったほど難しくなかったです。
Kanji weren't as hard as I thought.