finish后接动词时,不能用不定式,要用动名词,且该动名词要用一般式,不用完成式：
Have you not finished speaking?你还没讲完吗?
He hasn’t finished writing his book.他那本书还没写完.
注：当finish之后的动名词带有宾语时,有时可省去动名词(如果意义清楚的话)：
He has finished (doing) his work.他把工作做完了.
——摘自《英语常用词多用途词典》金盾出版社