网友这个问题，我准备用较长的篇幅解答。

第一个问题：

He fell in love with Mary the first time he saw her.(他对玛丽一见钟情.)
【答】名词词组the first time 可以充当连词，引导时间从句，本句用法便是。主句和从句动作，发生的时间非常紧凑。原翻译固然很好，为了更好理解句意，我直译为：“他第一次见到玛丽时，他就爱上了她。”

由time 组成的这种特殊结构，叫做“不是连词的连词”，之所以这么说，是因为the first time 不是真正的连词，而是一个名词词组，但是它在句中确实起到了连词的作用。

常见的由名词time 构成的“连词”：

the time, the first time, next time, any time, every time，each time, the last time, from the time, by the time 等，都可以作连词用，引导时间状语从句。

The (very) first time I climbed onto the wall, I felt nervous.

我第一次爬到墙上去时，感到胆怯。　　　

Every time I catch a cold, I have pain in my back. 

我每次感冒背就痛。

Any time you come to London do look me up.  

你无论什么时候到伦敦来，一定要来看我。

I recognized you the minute I saw you. 

我一见你就认出了你。　　　　　

Next time you come, you will see the scientist. 

你下次来时就会见到那位科学家。　　　　

You may come back any time you want to. 

你想回来随时可回来。　　　　

Each time the tourist traveled by boat he got seasick. 

这位旅客每次坐船行时都晕船。　　　　

The last time she saw James, he was lying in bed. 

她最后一次看詹姆斯时，他躺在床上。　　　　

The truck will have arrived by the time you have all the things packed up. 

到你把一切东西都捆好时，卡车也就来了。　　　　

第二个问题：

It is the first time that I have heard the news. 这是我第一次听说这个消息.

It was the first time that he had been to Beijing. 这是他第一次去北京.

【答】以上两句中，the first time 是先行词，后面的that 从句是定语从句。It 是“代词”，可以换成this 或that。详细讲解如下：

“This is the first time that...” 句式中，that 从句要用“现在完成时”。我们分析这个句子：This is the first time that I have visited Beijing. 这是我第一次参观北京。

【结构分析】

This is the first time 为主句，that I have visited Beijing.为定语从句，修饰the time，that 为关系副词，可以省略。

基本变式：This (It, That) is the first (second, third) time that ...

【时态分析】

This (It, That) is the first time that...跟与现在完成时连用，这体现了“现在完成时”的另一个特点：对过去经历的总结。意味着从过去某个时间到说话时的经历总结（也可能是人一生所经历），这跟现在完成时的“动作发生在过去，一直持续到现在”有某种关联，只不过是强调次数和经历而已。例如：

This is the first time in my life that I have taken part in such a grand celebration.这是我有生以来第一次参加如此盛大的庆典。

Although it is not an official Olympic event, this is the first time that Wushu has come so close to the Olympics.虽然这不是官方奥运比赛，但这是第一次武术距离奥运这么近。

This is the first time that the three leaders have met together and the first time that President Roosevelt has met Marshal Stalin.这是三巨头的第一次会面，同时也是罗斯福总统与斯大林元帅的首次会面。

This is the first time that a study has set out to examine whether giving up smoking has impact on memory.该研究首次着手检验戒烟是否对记忆有影响。

But this is the first time that we’ve been able to look at everything.但这是我们第一次看到全景。

This is the first time that they’ve ever had a truly stable home where they put their heads down on the same pillow each night.这是第一次他们拥有了一个真正固定的住所，每天晚上他们都躺在同一个枕头上睡觉。

This is the first time that he has written in English.这是他第一次用英语写作。

It is the first time that China has objected to manoeuvres in the area.这是中国第一次反对在此区域举行的军事演习。

It is the first time that Mrs Obama has given her approval to the work of a single company.这是奥巴马夫人第一次对一个独立公司的工作给予称赞。

It is the first time that such a large group of illegals has been uncovered.一下子揪出如此多的非法者，还是首次。

It is the first time that Stalin has left Russia since the Revolution.这也是自十月革命以来，斯大林第一次离开俄国。

It is the first time that we have talked about this issue face to face.这是我们第一次面对面地谈论到这件事情。

It is the first time that I have received your letter.那是我第一次收到你的来信。

It is the first time that he has performed on such a big stage.这是他第一次在如此大的舞台上表演。

It is the first time that she has ever lived in a city in her entire life.这是第一次她完全的生活在城市里。

It is the first time that I have been invited to attend such an important meeting.这是我第一次被邀请参加这么重要的会议。

That is not the first time that the earthquake potential of a fault has been underestimated.这并不是第一次低估地震的潜力。

That is the first time they have experienced that.这是他们第一次经历那件事。

This is the third cake you have eaten. 这你吃的第三块蛋糕了。

同理，如果主句用“一般过去时”，那么从句应当使用“过去完成时”，体现“过去的过去”这个语法特点。例如：

It was the first time that she had sung in public. 那是她首次公开演唱。

It was the first time that she had lived independently. 那是她第一次独立生活。

It was the first time that he had wept in nineteen years. 那是他19年来第一次流泪。

It was the first time that I had written with real passion. 这是我第一次满怀热情写作。

It was the first time that the black boy had tasted freedom. 这是黑人男孩第一次尝到自由的滋味。

It was the first time that little Franz had listened so attentively. 那是小弗朗士第一次如此用心地听讲。

This was the first time he had confronted an armed robber. 这是他第一次面对一个武装劫匪。

This was the first time I had been treated with such respect. 我是第一次受到这样的礼遇。

She was astonished; this was the first time she had heard of such things. 她大吃一惊；她第一次听说过这样的事。

This was the first time I had seen such a lot of snow. 我第一次见过这么大的雪。