How did you know that?

[Ali Smith]

שלום!

If someone surprises you by displaying knowledge you had no idea he had, what would be the idiomatic way of expressing this surprise in Hebrew? For example,

X: אתה מזרחי, נכון?
Y: How did you know that?

My guess is ek yadata?

אני מודה לכם מאוד

 

[slus]

Yes.
איך ידעת?
E(i)kh yada(a)ta / yada(a)t

 

[Ali Smith]

Thanks. Yeah, I'd forgotten that a guttural letter takes a compound shva instead of an ordinary shva. So, the formal pronunciation would be yada'ata while yadata would be the colloquial one, right?

 

[slus]

Right

 

[Abaye]

This is inaccurate. Why won't you look at a verb conjugation table like this one of the Academia (later, the site seem to have a technical problem right now).