一方は知っているが他方は知らない。の英語

I know one of them but not the other.

a wiseacre

He knows nothing, and yet he talks as if he knew everything

He talks as if he knew everything while he knows nothing at all.

There are things you're better off not knowing.

Do I know that man? I should rather think so.

Do I know him? I should rather think so

Yes, rather.

That still isn't really known by anyone.

I don't know it. Nor does he.

I don't know and neither does he.

Where ignorance is bliss, 'tis folly to be wise.

of an act, feigning ignorance

Pretend you don't know anything.

I kept the matter to myself.

Some people think they know everything.

I wouldn't know.

To put it succinctly, I don't know, and I don't want to know.

I kept the knowledge from everybody

I kept the knowledge to myself.

Nobody knows that yet.

I don't know both.

of a person, blatantly pretending not to know something even though she or he does know it

There are things you're better off not knowing.

I know him by name, but not by sight.

not knowing or perceiving

As if you didn't know!

As if you knew everything!

There is no one but knows it.

One may as well not know a thing at all, as know it but imperfectly.