- Well, as a matter of fact, I can tell you, it will happen.
- How do you know?
- Well, we won't go into that.

9 seconds sound clip from the The Shop Around the Corner (1940) movie soundboard.

You can hear this line at 01:31:33.973 in the Blu-ray version of the movie.

Quote context

[...]

- You see, my mistake was I didn't realize that the difference between this glamorous lady and me was that she was with the Comedie Francaise and I was with Matuschek and Company.

- Oh, well, that's all forgotten now.

- So now you're going to see your girlfriend. By the way, is it serious?

- Yes, very.

- Maybe, maybe we'll both be engaged Monday morning.

- I think we will.

- Well, I don't want you to misunderstand me. I just said in my case it might happen.

- Well, as a matter of fact, I can tell you, it will happen.

- How do you know?

- Well, we won't go into that.

- Mr. Kralik, what do you mean you know?

- Well, I guess I might as well tell you. He came to see me.

- Who?

- Your fiance. Yes, yes, he came last night. You shouldn't have told him who I am. I spent a very uncomfortable hour.

- Apparently, he didn't believe it when you wrote that I meant nothing to you.

- I can't get it into my head.

- Coming to see you? Oh, no, that doesn't sound like him at all.

[...]