in the end~In the end,he killed himself.in the end =finally, at last.最后他還是自殺了
at the end of~At the end of this street a body lay there.街尾躺著一具尸體
by the end of ~by the end of this year,they will have finished work on the new stadium(在今年年底工人們很把路鋪好）注：have+過去分詞表將來完成時
by表：在某時之前,并不晚于某時的任何時間.只能與時間點的名詞或詞組連用.在肯定與否定句中有區(qū)別
i will have left by monday到星期一我將離開（星期一之前的任何時間）