本気じゃないんだよな。の英語

You can't be serious.

I don't feel like it.

I don't have that kind of feeling.

What'll they think of next?

Don't talk like that.

That isn't cool.

I'm not stupid.

I'm not a fool.

I can't help worrying about that.

It's not a difficult problem.

It isn't a difficult problem.

No, that's not true.

There is really nothing.

I don't really care that much.

I am not an idiot.

That can't be true.

That isn't bright.

I am not an idiot.

Isn't it true?

The rumor can't be true.

I'm no fool.

It cannot be true.

It can not be true.

It can't be true.

It makes no sense at all.

There is not the slightest suspicion of it.

It can't be true.

I am not proficient.

I am not clumsy.

I don't believe such things to exist.