imposter

那个冒牌医生通过伪造证书在医院工作了几个月。

The ___imposter worked at the hospital for months using fake medical credentials.

那个自称是医生的冒牌货实际上从未上过医学院。

The man claiming to be a doctor was actually an ___imposter who never attended medical school.

那个自称是医生的骗子被警方逮捕了。

The man who claimed to be a doctor was actually an ___imposter and got arrested by the police.