わけにはいかないcan't very well; can't very well not
You could do it, and you might like to, but duty, manners or your position won't let you: "I can't very well…". After a negative verb it becomes "I can't very well not", which comes out as "have to".
can't very well
My staff are still working, so I can't very well be the only one to go home.
can't very well not
If a close friend asks me that earnestly, I can't very well refuse to help.
Can't very well
Verb dictionary form + わけにはいかない
帰るわけにはいかない. Polite わけにはいきません, past わけにはいかなかった.
Can't very well not
Verb ない-form + わけにはいかない
行かないわけにはいかない, "I have to go".
You could, but you can't
Nothing physical is in the way. What stops you is your job, a promise, good manners, or what people would think. It is mostly said about yourself.
I can't drink alcohol.
Your body can't take it. There is no choice to make.
I drove here today, so I can't very well drink.
You could, and you might like to. Driving home is what stops you.
The plain "can't" is said here too: 今日は車なので、飲めません. わけにはいかない adds that duty, not ability, is what stops you.
Not said: 漢字が
(I don't know the kanji, so I can't read this book.)
Only ability is in the way, so it is 読めない.
As a doctor, I can't disclose a patient's information without permission.
I can't give up now.
Also resolve: giving up is not an option.
I'll get this today.
No, I couldn't let you do that. I'll pay my share.
そういうわけにはいきません, "I couldn't possibly", politely turns down an offer or a way out.
わけにもいかない
With も, one way out is closed and so is this one: "can't very well… either".
I can't break my promise, but I can't very well keep quiet about what is going on either.
After a negative: have to
A negative verb in front turns it around. Now you can't very well leave the thing undone, so you do it, often without wanting to.
I have an important meeting first thing tomorrow, so I can't very well go to tonight's drinks.
Going is ruled out.
The department head invited me, so I can't very well not go to tonight's drinks.
Not going is ruled out. You go.
Are you working late again today?
The deadline is tomorrow, so I have to finish it tonight.
Three kinds of "have to"
English "have to" covers all three. One meeting, said three ways.
Since I made a promise, I can't very well skip tomorrow's meeting.
なければならないN5
The plain "must": a rule or a need, nothing more.
Everyone has to attend tomorrow's meeting.
しかないN3
The only thing left to do: every other option is gone.
There is no one to go in my place, so I'll just have to attend tomorrow's meeting myself.
The four わけ
Four endings are built on わけ, the reason behind something, and they mean quite different things.
わけだN3
"So that's why", "no wonder", "which means": it all adds up.
The window is open. No wonder it's cold.
わけがないN3
"There's no way": it couldn't be so. Spoken: わけない.
It's this cheap, so there's no way it's the real thing.
わけではないN3
"It's not that…", "not exactly": it takes back a conclusion without saying the opposite.
This job is not exactly easy, but it is rewarding.
Check yourself
1What does this mean?
先生に
Choose an answer to see why.
2Which one fits?
この
Choose an answer to see why.
3Which reply fits?
A
Choose an answer to see why.
More sentences
My daughter's graduation ceremony is tomorrow, so I can't very well work late tonight.
As a journalist, I cannot publish unverified information in an article.
I made a promise to a customer, so I can't very well close the shop now.
I promised to attend, so I can't very well miss the ceremony.
My mother is in the hospital, so I have to help at the shop for a while.
The person in charge was absent yesterday, so I had to step in.
As team captain, he too has to take responsibility.