I forgot my bag taking off the plane

I left my bag on the ground while the plane taking off.
飞机起飞的时候我把行李给丢在了候机厅

I left my bag on the plane while getting off.
下飞机的时候我把行李丢在了飞机上

forgot 应改为 left。

forgot sth. 是为抽象的事物。

应该是动词搭配的错误

这里应该用forget to do sth

句子改为：I forgot to take off my bag from the plane

完全不makes sense

应该是 I left my bag behind me when i was getting off the plane.

leave...behind... 是 忘记拿...
take off 是（飞机）起飞
我想你是想说下飞机吧 那就应该是get off