They were playing by the door a short time ago.(改为否定形式的疑问句）
问题描述：
They were playing by the door a short time ago.(改为否定形式的疑问句）
如题.
答
were not they playing by the door a short time ago
一般疑问句的方法是 把BE 动词或 助动词提到 主语的前面.
再变成否定形式的话 就在 BE 动词或 助动词的后面加上 not 就行了.