英语语法he said with a smile as if he were talking aboutan old f

一楼回答有误：
1 he是主语,said是谓语,with a smile是方式状语,as if he were talking about an old friend也是方式状语,as if 后用的是虚拟语气,表达与事实相反.
2 considering that she had had so many delays.=if we consider that she had had so many delays,是条件状语,even this was remarkable是主句,considering that she had had so many delays常放在句首.
下面给你补充一下as if的用法
as if 从句的用法
1．在look,seem 等系动词后引导表语从句.如：
She looks as if she were ten years younger．
她看起来好像年轻了十岁.
It seems as if our team is going to win．
看来我们队要胜了.
2．引导方式状语从句.如：
She loves the boy as if she were his mother．
她爱这男孩,就好像她是他的母亲一样.
The child talked to us as if he were a grownup．
那孩子跟我们谈起话来,像个成年人似的.
二、as if 还可用于省略句中
如果as if 引导的从句是“主语＋系动词”结构,可省略主语和系动词,这样as if
后就只剩下名词、不定式、形容词（短语）、介词短语或分词.如：
He acts as if （he was） a fool． 他做事像个傻子.
Tom raised his hands as if （he was going） to say
something．
汤姆举起手好像要说什么.
She left the room hurriedly as if （she was）angry．
她匆忙离开房间好像生气的样子.
三、as if 从句的语气及时态
1．as if 从句用陈述语气的情况.
当说话者认为句子所述的是真实的或极有可能发生或存在的事实时.如：
It sounds as if it is raining． 听起来像是在下雨.
He talks as if he is drunk． 从他谈话的样子来看他是醉了.
2．as if 从句用虚拟语气的情况.
当说话人认为句子所述的是不真实的或极少有可能发生或存在的情况时.从句虚拟语气动词时态的形式如下：
（1）如果从句表示与现在事实相反,谓语动词用一般过去时.如：
You look as if you didn’ t care．
你看上去好像并不在乎.
He talks as if he knew where she was．
他说话的样子,好像他知道她在哪里似的.
（2）从句表示与过去事实相反,谓语动词用“had＋过去分词”.如：
He talks about Rome as if he had been there before．
他说起罗马来好像他以前去过罗马似的.
The girl listened as if she had been turned to stone．
那女孩倾听着,一动也不动,像已经变成了石头似的.
（3）从句表示与将来事实相反,谓语动词用“would／could／might＋动词原形”.如：
He opened his mouth as if he would say something．
他张开嘴好像要说什么.
It looks as if it might snow． 看来好像要下雪了.
considering用法
considering
prep.
就...而论,照...说来,鉴于
That is not so bad,considering (the circumstances).
照（实情）说,那还算不错(从多方面说来,还过得去).
adv.
[口]细想起来,认真说； 概括而论； 总而言之
Yes,her speed was really quite good,considering.
是的,认真地说,她的速度相当不错了.
conj.
考虑到
C -he's only been learning English a year,he speaks it very well.
考虑到他只学了一年英语,他说得是很好的.

considering that she had had so many delays.这个做状语，是这个人考虑到她有如此多的延误
he said with a smile as if he were talking aboutan old friend.
even this was remarkable他便微笑着说,好像他是在谈论一位老朋友。虽然这很不平凡

he （主语）said（谓语） ，with a smile， as if he were talking about an old friend.（从as if到结束，这个部分是一个宾语，由as if 引导的名词从句）
这句话其实就是个主谓宾结构，只是宾语比较特殊。
even this was remarkable(到这里为止，这个部分是个be句型的简单句)，considering...