other N4 common casualpolitewritten

少なくない — not few / quite a few

少なくない・すくなくない

Meaning

not few / quite a few / no small number — the negative of 少すくない, used to mean 'a fair amount'

この意見いけんに賛成さんせいする人ひとも少すくなくない。

Quite a few people agree with this view, too.

Attaches to	Form	Example
い-adjective 少すくない → negative	少すくない → 少すくなくない	例れいは少すくなくない (the examples are not few)

こういう間違まちがいをする学生がくせいは少すくなくない。

There are quite a few students who make this kind of mistake.

彼かれに反対はんたいする声こえも少すくなくなかった。

There were no small number of voices against him, either.

A litotes: 'not few' understates '多おおい (many)' for a measured, often written tone. The same move gives 少すくなからず ('not a little') in more formal prose.

Jengo shows 少なくない the way you actually meet it: inside real Japanese sentences, so it sticks instead of staying an abstract rule.

Sources Compiled from published Japanese grammar references.