Not exactly, not necessarily, it's not that I don't
A plain yes or no often says too much. わけではない, とは限らない and というものではない are a partial "no": they take back part of a claim, and わけではない is the one to start with. The other forms are a partial "yes": "I can, I suppose", "I did, but".
| Form | What it says | Where |
|---|---|---|
| わけではない | "It's not that…": it takes back a conclusion | Everywhere |
| とは限らない | "Not always", "not necessarily": it isn't certain | Everywhere |
| というものではない | "It isn't that simple": one thing alone doesn't settle it | Opinion pieces, advice, arguments |
| ないことはない, なくはない | "I can, I suppose": a weak yes | Conversation above all |
| ことは～が | "I did, but": the bare fact, then the catch | With けど, conversation; with が, writing too |
| ないでもない | "I can see that, up to a point": a stiffer weak yes | Essays, novels, careful speech |
| ないものでもない | "I might, if…": no promise | Essays, novels, negotiations |
わけではない: it's not that…
Full pageわけではない・
わけではない takes back a conclusion the other person might jump to. It doesn't say the opposite, so it is softer than a flat "no" and often means "not entirely". In conversation it is usually わけじゃない, and というわけではない means the same.
This job is not exactly easy, but it is rewarding.
It's not that I particularly dislike it, but I don't eat it much.
This doesn't say you like it. It only takes back "dislike".
Do you not want to go on next month's trip?
That is not it. My work schedule has not been decided yet.
With いつも, 毎日 or みんな it is "not always", "not every day", "not everybody".
I'm never home on Sundays.
A plain negative covers every Sunday.
I'm not always home on Sundays.
Only the "always" is taken back.
とは限らない: not always, not necessarily
Full pageとは限らないN3
とは限らない says that something isn't certain: a rule people take for granted has exceptions, or a guess may be wrong. You grant that it is often true and hold back the "always". 必ずしも often comes earlier in the sentence, and tells you that a "not necessarily" is coming.
A quiet place isn't necessarily easy to concentrate in.
The forecast says sunny, so we won't need umbrellas.
Not necessarily. The weather in the mountains changes quickly.
After a negative it warns that the thing could happen.
Even if you prepare thoroughly, there's no guarantee you won't fail.
というものではない: it isn't that simple
Full pageというものではない・
というものではない rejects a rule for being too simple, such as "say sorry and it's settled". Saying sorry may count, but it doesn't settle the matter. Most often it follows ば, as in …ばいいというものではない. In casual talk it shortens to ってもんじゃない, often a telling-off.
It's not as if saying sorry is all it takes.
It's not as if cheap is all that matters, you know.
Where it goes wrong
English "not necessarily" can be said of a fact you know, such as your own taste. とは限らない can't: a fact you know takes わけではない.
Not all non-drinkers dislike alcohol.
A rule about people in general. It has exceptions.
I don't drink, but it's not that I dislike alcohol.
One person, and you know the answer.
Not said: 私は
(I don't drink, but I don't necessarily dislike alcohol.)
Your own taste is neither a rule nor a guess.
というものではない, too, needs a rule to reject.
Not said: 会議を
(I will miss the meeting, but that does not mean I oppose the proposal.)
It is 反対しているわけではない.
からといって: just because … doesn't mean
Full pageからといってN2
からといって grants a reason and refuses the conclusion drawn from it, so it often comes in front of わけではない, とは限らない or というものではない. English often says "doesn't mean" for all three.
Living in Japan doesn't mean your Japanese gets good.
It doesn't follow, and no more is said.
Just because a restaurant is famous doesn't mean the food is good.
It often follows, but not every time.
Just because someone went to a famous university doesn't mean they can get results at work.
The university counts, but it isn't enough.
ないことはない and なくはない: a weak yes
Full pageないことはない・
ないことはない is two negatives that make a weak yes: something is possible, or true up to a point, and you hold back a wholehearted yes. なくはない is shorter and means the same. A "but" usually follows.
I could go tomorrow, I suppose.
A weak yes. Something is holding you back.
Can you help with the move on Saturday?
I could, but only in the afternoon.
Not "sure, no problem": B is holding back.
I can see how he feels, up to a point, but I can't agree with the way he said it.
分からなくもない, with も, is the same weak yes.
わけではない after a negative is a weak yes too, and often begins a gentle "no".
It's not that I don't want to go, but I have plans that day…
You do want to go, more or less.
ことは～が: I did, but…
Full pageことは～がN3
ことは～が says the same word twice: a full yes, but only to the bare fact, whereas ないことはない is a weak yes. Then が or けど brings the catch, and that half is the point.
I did watch the movie, but I fell asleep several times during it.
It's good, I'll give it that, but it's a bit pricey.
Faint praise. Saying it twice doesn't mean "really" or "very".
ないでもない and ないものでもない: a stiff weak yes
Full pageないでもない・
ないでもない is a stiffer ないことはない. It mostly goes with thinking and feeling, and two phrases are everyday: 分からないでもない and 気がしないでもない. ないものでもない allows that you might do something if the conditions are right, and promises nothing.
I can understand her decision up to a point, but I can't agree with it.
I do get the feeling it's a little too expensive.
Depending on the terms, I might take it on.
Look-alikes: わけがない and ことはない
わけがないN3
"There's no way": a flat no, not a soft one.
There is no way he would believe a story like that.
ことはないN3
After the dictionary form, not a negative, it is "no need to".
There's no need to worry about it all by yourself.