あまり〜ない details

not much + write + not

amari kakanai

not much; not very — a degree adverb licensed only by a negative predicate

meaning: not write much

お酒さけは好すきだが、家いえではあまり飲まのまない。

osake wa suki da ga, ie de wa amari nomanai.

I like a drink, but at home I do not drink much. neutral

その映画えいが、あんまり面白おもしろくなかった。

sono eiga, anmari omoshirokunakatta.

That film wasn't all that interesting. casual

Examples

not much; not very — the speaker admits some of the quality or act, but little of it

お酒さけは好すきだが、家いえではあまり飲のまない。

osake wa suki da ga, ie de wa amari nomanai.

I like a drink, but at home I do not drink much. neutral

その映画えいが、あんまり面白おもしろくなかった。

sono eiga, anmari omoshirokunakatta.

That film wasn't all that interesting. casual

今年ことしの夏なつはあまり暑あつくありませんでした。

kotoshi no natsu wa amari atsuku arimasen deshita.

This summer wasn't very hot. neutral

その件けんにつきましては、あまり詳くわしくは存ぞんじておりません。

sono ken ni tsukimashite wa, amari kuwashiku wa zonjite orimasen.

I am not very well informed about that matter. formal

あまり quantifies a noun under the same negative — あまり時間じかんがない,
あまり人ひとがいない.

全然〜ない
Both wait for a negative to complete them, but あまり only scales the predicate down while 全然 wipes it out — あまり食たべない leaves food on the plate, 全然食たべない leaves the plate untouched.
少しも〜ない
少しも denies the degree outright and is the emphatic choice; あまり concedes a residue — 少すこしも痛いたくない says there is no pain at all, あまり痛いたくない admits a little.

あまり（に）
One surface, opposite polarity — the あまり of 〜あまり(に) is a POSITIVE degree ("so much that…") that follows its cause and demands a result clause (緊張きんちょうのあまり、声こえが震ふるえた), while this あまり precedes the predicate, is licensed by the negative alone, and causes nothing.