The boy went out of the yard.这句话中out是介词还是副词?

问题描述:

The boy went out of the yard.这句话中out是介词还是副词?

The boy went out of the yard.
out of 是复合介词.翻译如下:
这个男孩离开了院子.
此句中out 不能单独分析是介词还是副词.