Charlize Theron becomes US citizen

South African-born actress Charlize Theron has become a US citizen.

The Oscar winner said she was thrilled to have passed a citizenship course after living in the country for more than a decade.

She told talkshow host David Letterman: "I've always wanted to be one, they just didn't want to take me. You're stuck with me now!

"It's quite a process - you have to work hard, you have to study up. You have to know your stuff - you've got to know your senators, how the government works.

"They give you a test. It is what you should know and I think it is good that they do it. If you live here you should know your stuff. I did incredibly well, I studied up and I was right there with my answers before he had even finished the questions."

However, she added that she had frozen at one point when asked to write a simple sentence, saying: "It was all going fine until the interviewer said, 'Take this piece of paper and write, 'It's a sunny day'.' I was like, wait a second, this isn't in the book - I didn't study for that!

"It was one of those really weird feelings where you completely doubt yourself. I forgot how to speak English, I was thinking does sunny have a double n?"

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