なくもない
なくもないnaku mo naineutral
Same meaning1
it's not that X can't; possible after all
All examples3
it's not that one doesn't — a partial yes, from two negatives
彼の言い分も、分からなくもない。
kare no iibun mo, wakara naku mo nai.
As for his side of it, it's not that I don't understand. neutral
面倒だけど、頼まれれば手伝わなくもないよ。
mendou da kedo, tanomarereba tetsudawanaku mo nai yo.
It's a hassle, but if you ask me, it's not like I wouldn't help. casual
ご提案の趣旨は理解できなくもありませんが、時期尚早かと存じます。
go teian no shushi wa rikai dekinaku mo arimasen ga, jikishousou ka to zonjimasu.
It is not that I fail to see the point of your proposal, but I believe it premature. formal
How it's formed2
All forms5
なくはないnakuhanaialternant
味わわなくはない
は in place of も softens it a notch (行かなくはない grants the fact more plainly). Neither form is more spoken than the other.
ないでもないnaidemonailiterary
味わわないでもない
The same trick on plain ない, stiffer and mostly written — 考えられないでもない.
ないものでもないnaimonodemonailiterary
味わわないものでもない
Stiffer still, with the air of a general truth. Almost only seen in written argument or negotiation.
- pastなくもなかったnakumonakatta
味わわなくもなかった
- politeなくもありませんnakumoarimasen
味わわなくもありません
Notes
well go, with doubt only in how far.