Looking on the internet deeply has found these results:

And how do you know this? is the most popular phrase on the web.

and you know this how? 1335,000 results on the web	And how do you know this? 11,280,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
Word on the street. And you know this how? And you know this how? And you know this how? And you know this how?	And how do you know this? And how do you know this? You got something? And how do you know this? I caught them together two days before she died. And how do you know this? And how do you know this?

and you know this how?

1335,000 results on the web

And how do you know this?

11,280,000 results on the web

More popular!