What is the meaning of 确定 in 你确定你是外国人? I was told this sentence:


  你确定你是外国人→_→


When I looked up the meaning of 确定 it said it meant definite/certain. So, my guess for this sentence is:


  Are you certain you are a foreigner/are you definitely a foreigner?


Am I right? Why was 确定 used in this context? What is its actual meaning?
確定 as a verb means "to determine" 

「確定你是外國人」literally means "determined you are a foreigner" 

To illustrate the meaning of 「確定」 as a verb more clearly, let's look at the following sentences:  

「可以確定這是假貨」( can determine this is a fake)

「可以肯定這是假貨」( can be certain that this is a fake)

「名單已被確定」( the list has been determined)

「名單已被確認」(the list has been confirmed) 

"Are you certain you are a foreigner?" -「你肯定你是外國人?」