意思完全不同的
after all
畢竟, 終究, 歸根結(jié)底
1.You should forgive him for his forgetfulness; after all, he is over seventy.
你應該原諒他的健忘癥,畢竟他已經(jīng)七十多歲了.
2.You should be charitable with him; he is a child after all.
你應該對他寬容些,畢竟他還是個孩子.
3.I was so tired after all that gardening that I was out for the count for ten whole hours last night.
把花園里所有的活干完后,我實在太累了,昨晚沉睡了足足有10個小時.
at all
完全, 全然; 究竟; 竟然; 在任何程度上
1.I don't think that's a bad idea at all.
我看這完全不是個壞主意.
2.It doesn't matter at all.
這根本沒什么關系.
3.He is not at all alive to the danger he is in.
他完全沒有意識到他處境的危險.

at first
首先, 最初
1.We didn't trust him at first, but his charming manner completely disarmed us.
我們開始時并不信任他,但他令人愉快的舉止完全消除了我們的疑慮.
dict.cn
2.At first he refused to accept any responsibility but he ended up apologizing.
最初他拒不承認有任何責任, 到頭來還是道了歉.
3.At first we used hand tools.
首先我們使用手工工具.

first of all
首先
1.Marriage is, first of all, a contract which must be governed by justice.
婚姻首先是一種契約,它必須以公正為制約.
2.First of all, we are today as Senator Kennedy has admitted, the strongest nation in the world militarily.
首先,正如肯尼迪參議員所承認的那樣,我們是世界頭號大國
3.First of all, let me tell you the news.
首先,讓我告訴你這個消息.