定位段落主题是我们在雅思阅读中必须掌握的一项技能，尤其是在雅思考试的文章中，更是必须迅速抓准主题句，提取文章主干，缩短阅读时间，精准答题方向。那我们应该怎么定位呢?首先，我们应该明确段落主题的大致位置，那么在哪些地方是段落主题常常出现的位置呢?

段落主题句出现得最多的位置就是段首。

英语文章中最多的就是演绎型的写法，因为西方人喜欢开门见山，所以他们常常在每一段的第一句话就先交代出这段话的主旨。这是最简单的，也是最常见的主题句位置，如下面这个例子：

As a child grows up, he learns how to behave in ways that is appropriate to the society into which he is born. That is to say, he acquires the patterns of behavior that are accepted as normal in his society. This process of social learning is generally referred to as socialization. By socialization, then, we mean the process whereby individuals learn the rules, values and practices of the society in which they live.

上面这段话中的第一句就是对整体段落大意的一个介绍;从第二句话中的“That is to say”可以看出来，第二句话是对第一句话的解释;第三句话中的“This process”也是代指的前一句话中的学习，成熟过程。而最后一句话也是对社会化的一个解释，所以也可以确定第一句话就是段落的主题句。

除了第一句之外，主题句也可能出现在段首位置的第二句。那什么时候会出现这种情况呢?分成三种情况：

(1)当首句是问句时;

(2)当首句是过渡句时;

(3)当次句为转折句时。

在这些情况下，第二句话都会比第一句话更重要，所以主题句也更可能出现在第二句话中。例如下面这句话：

What then makes people left-handed if it is not simply genetic? Other factors must be at work and researchers have turned to the brain for clues. In the 1860s the French surgeon and anthropologist, Dr Paul Broca, made the remarkable finding that patients who had lost their powers of speech as a result of a stroke (a blood clot(凝结) in the brain) had paralysis(麻痹) of the right half of their body. He noted that since the left hemisphere of the brain controls the right half of the body, and vice versa(反之亦然), the brain damage must have been in the brain’s left hemisphere, Psychologists now believe that among right handed people, probably 95 percent have their language centre in the left hemisphere, while 5 percent have right-sided language.

第一句话提问：“如果不仅是基因让人们习惯于用左手，那还有什么原因呢?”我们能预测出，接下来这段话应该就会给我们介绍除了基因以外的其他原因。正好第二句话说：“其他的因素也起到了作用，研究者将线索转向人类大脑方面。”所以能确定，所谓的“其他原因”就是指的“人类大脑”，所以主题句也就是第二句话。

另外一个常出现段落主题句的位置则是段尾。

这种现象常出现在归纳型的文章里。所谓归纳型，则是先陈述现象，最后总结规律。因此这类的文章通常会出现一些总结性的词：Therefore/ Hence/ Thus/ So/ Consequently/ Accordingly/ As a result/ As a consequence;或者会出现一些研究报告类的词组The research findings/ the study/ the investigation/ the analysis/ the evidences show/ reveal/ imply/ indicate/ suggest/ demonstrate / prove that…;甚至有的会直接出现总结型主题句：In short/ In general/ All in all/ To sum up/ In summary/ On the whole…我们一起分析下面这个例句：

The only species which demonstrated(证明，证实) near normal productivity(生产力) was Cassin’s Auklet(卡森的海雀), in which the value for 1998 exceeded the long-term mean by 16 percent. However, given that very few Cassin’s Auklets attempted to breed(生产，繁衍), island-wide offspring(后代) production was extremely low. In short, these observations were quite similar, with slight variations, to observations made on the Farallon(法拉龙) seabird community in other severe E1 Nino years.

在这段话的第一句中，我们就发现了刚刚总结过的一个关键词“demonstrated”，但是我们不难发现，这个地方是“demonstrated”是属于which这个定语从句中的，所以不是对整段话，甚至整篇文章的总结。

所以排除了第一句话是主题句的可能性。第二句出现了转折，那我们又知道转折句后面的肯定比前面重要，所以接着往下看这句话。但是，看完这句话之后，我们不难发现，最后一句话用了一个总结型的句子：“In short”，所以一下就能确定该段话的主题句就是最后一句话。

掌握好这些判断主题句的方法能帮我们更快地确定段落主题，并节约阅读时间，有更多精力放在做题上。在雅思阅读中能快速地帮我们解答的配对题，主旨题等!希望广大考生也能积极总结积累，不断进步。