By the end 和In the end 的区别详细

1.in the end意思“最后、终于”。它的意思相当于finally, at last。它往往表明事情的结局,在句子中一般单独使用。
如:Xiao Ming passed the exam in the end. 最后小明通过了那次考试。
Ice becomes smaller and smaller until in the end it disappears completely. 冰变得越来越小,直到最后完全消失。
2.by the end of +表示时间的名词,意为“到……末为止,到……最后”,注意:如果of后面接表示过去时间的名词,那么本句的谓语必须用过去完成时态。
如:How many English words had you learned by the end of last term?到上学期末为止,你学会了多少个英语单词？
I had been to the Summer Palace three times by the end of last year.到去年年末我去过颐和园三次了。

in the end 可单独作为时间状语使用
如：In the end, we arrived. 最后我们终于到了。
by the end 要后面跟of+名词
by the end of last year 截至到去年年底

in the end = at last 最后的意思
by the end 到...为止
In the end ,she went to school late .最后,她上学迟到了
by the end of this year 到今年年底

上面的解释已经够清楚的了,特别是wzh868的解答很是详细.我完全赞同他
你要是还不明白不仿看看下面的oxford字典的解释,希望能对你有帮助
1 at the end of the day (BrE, informal) used to introduce the most important fact after everything has been considered: At the end of the day,