The `Devil Wears Prada` star - who developed the speech impediment at the age of seven - rarely struggles to speak in front of strangers but admitted she sometimes has problems getting her words out in front of family and friends.
Emily - who is married to `The Office` star John Krasinski - said: "Weirdly enough, I stutter less with a person I`m unfamiliar with. And then with my family or my husband it`ll come out more which is strange."
Although her episodes of struggling to speak are now rare, Emily admitted she had a tough time with her stutter when she was growing up.
She told Stella magazine: "As a child and early teen I didn`t speak as much - because I couldn`t. Maybe that was a good thing because I soaked it all up like a sponge. But I don`t remember it as a conscious thing. I think I just wanted not to talk. Too embarrassing."