Before I came to Beijing， I worked in Shanghai.

　　A    How long have you lived in Beijing？

　　A    你在北京住多久了？

　　B    I've been living and working in Beijing for seven years.

　　B    我在北京生活、工作已经七年了。

　　A    And before that？

　　A    在那之前呢？

　　B    Before I came to Beijing， I worked in Shanghai.

　　B    在来北京之前，我在上海工作。

　　A    Are you from Shanghai？

　　A    你是上海人吗？

　　B    Yes， I was born there and went to university there.

　　B    是的，我出生在那里，又在那里读的大学。

Notes

　　1 When you ask about something that started in the past but continues to the present time， you use the Present Perfect tense，e.g.： How long have you lived in Beijing？

　　/ How long have you lived in Beijing？； I have been here for seven years / I have been here for seven years.当你谈论从过去开始一直持续到现在的某件事时，用现在完成法时态。例如：How long have you lived in Beijing？ / 你在北京住了多久了？；I have been here for seven years /我在这里已经七年了。

　　2 If you are talking about something that is completely in the past，you use the Past Tense （sometimes called the Imperfect），e.g.： Before I came to Beijing， I worked in Shanghai / Before I came to Beijing I worked in Shanghai.如果谈论的事情完全发生在过去，则用过去时态（有时也叫做未完成时态），例如：Before I came to Beijing， I worked in Shanghai /在来北京之前，我在上海工作。

　　3 Usually when you talk about your birthplace or year of birth，you use the Past Tense， e.g.： I was born in Shanghai / I was born in Shanghai； I was born in 1977 / I was born in 1977.在谈论出生地或者出生年份时，通常用过去时态，例如：I was born in Shanghai / 我出生在上海； I was born in 1977 /我出生在1977年。