门口站着一位警察。 用英语怎么说

with a policeman standing outside

was的主语是your wife，而were的主语使you

There is a policeman standing by the door.

By the door stands a policeman.

wife是第三人称用is 过去时就是was

you是第二人称,用are,过去时就是were

门口站着一位警察。
There is a policeman standing at the door.

while时两个动作同时进行, 都用进行时(时态一致)
your wife = she 第三人称单数 is的过去时= was
you are的过去时= you were

There is a policeman standing the front of the door！

Police stood a door.

(There is) a policeman standing at the door.