Did he has fun in Beijing?改错

Did he has fun in Beijing?改错
Did he has fun in Beijing?改错

Did he has fun in Beijing?改错
has 改为have
前有疑问助词did,所以谓语动词用原形

has改为have。前面已经有助动词了，后面就直接用原形动词就可以了。

has->have

has改为have