when 问的是点时间。例:When did he move to our city? In 2009./ Three years ago./Last year.
How long 的答句为段时间。例: How long have you studied English? Since three years ago./ For three years.
when 问的是点时间。例:When did he move to our city? In 2009./ Three years ago./Last year.
How long 的答句为段时间。例: How long have you studied English? Since three years ago./ For three years.