逗号的妙用指的就是分句之间的衔接与连贯问题。句式的复杂多变要求我们在用英语进行表达时既要有简单句、并列句又要有复合句甚至复杂复合句。要构造句子结构的复杂多变就必须讲究分句间的衔接与连贯问题。逗号的妙用实质就是逗号后/前分句间衔接与连贯的六种技巧。
　　
　　一、非限制性定语从句的使用。例如：
　　
　1. Nowadays， the call for quality-oriented education is becoming widespread and the drawbacks of test-oriented education， which have aroused great concern throughout China， are becoming increasingly apparent.
　2. The sharp contrast hinges on the protection of the green house， which determines in a large measure the life and death of the lovely flower.
    3. This trend began during the Second World War， when several governments came to the conclusion that the specific demands that a government wants to make of its scientific establishment cannot generally be foreseen in detail.
　　逗号前后是我们表达构造复杂多变、精彩生动句子结构的突破口。上述三例中我们合理巧妙地运用了非限制性定语从句，使前后两个分句有机地连接起来，显得连贯、自然。例1用关系代词which（非限制性定语从句不能用that）代替逗号前整个分句的意思。这样就把原本要用两个句子来表达的信息通过定语从句压缩为一个主从复合句，显得简洁、不罗嗦。例2用关系代词which代替逗号前先行词the green house，通过非限制性定语从句进一步说明温室对于鲜花存活的重要性。例3中逗号前先行词是表时间，因此用关系代词when引导非限制性定语从句，将主要信息移置逗号之后，取得“尾重”或“末尾聚焦(end-weight)”的效果。其实学生对于非限制性定语从句的用法不可谓不熟，但可能就是缺乏用多种手段衔接分句的意识。
　　
　　二、非谓语动词做状语的使用。例如：
　　
　　1． By contrast， when removed from the green house， the protective umbrella， it struggles helplessly against the sudden attack of storms， only to wither away.
　　2． Parents are too eager to mold their kids， disregarding their individuality with a callous attitude toward their personal development.
　　3． School-age children are often seen carrying bulging bags on their backs， weighed down on their way to and from school every day.
　　非谓语动词有四种表现形式，即动词不定式、现在分词、过去分词和动名词。利用这几种非谓语动词形式（动名词不能做状语除外）做状语，能很好地突出信息，取得信息“末尾聚焦(end-weight)”的效果。例1用only加动词不定式表示出乎意料的结果，做结果状语。从而将备受溺爱的孩子们不更世事、不堪一击的惨状和盘托出。例2用现在分词做结果状语，表示一种必然的发展趋势，即结果在意料之中。例3用过去分词做伴随状语，将饱受应试教育摧残的学龄儿童那苦不堪言的情形栩栩如生地勾勒了出来，辛辣的嘲讽宛然可见。当然这几种非谓语动词形式也可放在逗号前面——分句或句子中间，如：
        4. Weighing both these arguments， I can come to the conclusion that there is no need to take so drastic a step as doing away with this custom. (现在分词做时间状语)
　　5. An old peasant， bringing his own food， volunteered as a guild for us.（现在分词做伴随状语）
　　非谓语动词做状语到底放在前还是后似乎没有绝对的要求。但一般来说，做伴随状语时可前可后；做原因状语时放在前面较多，间或放在后面；做时间状语时一般放在句子前部；做结果状语时一般放在后半分句；做条件状语时一般放在前面分句，等等。
　　
　　三、同位语或插入语的使用。例如：
　　
　　1. As is distinct from above， the number “13”， a long-held symbol of bad omen in the eyes of most westerners， seems to be plaguing them.
　　2. By contrast， when removed from the green house， the protective umbrella，
　　it struggles helplessly against the sudden attack of storms， only to wither away.
　　3. Specifically， the number “6”， as they strongly believe， is closely associated with smoothness in the Chinese culture.
　　同位语或插入语一般插在主谓语之间，一般由名词词组（如例1、2）、介词词组（如in my opinion， in other words等）、从句（如例3）、不定式短语、现在分词短语充当。它们能起到补充说明的作用。除此之外，插入语还可对整句话表示解释，如：
　　4. There were twenty people present， to be precise.（不定式短语做插入语）
　　5.Roughly speaking， these countries are the most densely-populated in Asia.（现在分词短语做插入语）
　　
　　四、With结构的使用。例如：
　　
　　1．We now live in a society where competition in the job market rages， with graduates and job-hunters from all walks of life scrambling for desirable jobs.
　　2． As described in the picture， an American girl is wearing a Chinese costume characteristic of some minority group， with a sweet smile on her face.
　　3． These children can set their hearts at ease， with everything well- arranged by their parents.
　　4． With education on all sides being enforced， our young college students will grow up to be qualified not only in their fields but， more importantly， in moral cultivation.
　　5.He entered upon the new enterprise cautiously， with his eyes wide open.
　　With结构总的说来有五种形式，即：With+名（代）词+现在分词（如例1、4），With+名（代）词+过去分词（如例3），With+名（代）词+介词短语（如例2），With+名（代）词+副词或形容词（如例5），With+名（代）词+不定式。With结构可表原因（如例1、3）、伴随或方式（如例2、5）、条件（如例4）等。

        五、独立主格结构的使用。例如：
　　
　　1. Rosy dreams shattered， they are bewildering at the junction: “To be or not to be? That is a question”—— Hamlet’s perplexed monologue are echoing in their ears.
　　2. “Just listen to this，” she will say， her eyes glowing， her warm fingers pressed to my palm to hold my attention.
　　3. The U.S. population expanding dramatically， the species of its wildlife has witnessed a corresponding decline in a span of two centuries (1800-2000).
　　4. He went off， gun in hand.
　　5. The floor wet and slippery， we stayed outside.
　　6. The meal over， prayers were read by Miss Miller.
　　两个或两个以上分句间如果主语不一致时要用独立主格结构。所谓“独立主格结构”实质就是带自己主语的非限定分句和无动词分句。它按结构形式分为不定式“独立结构”、-ing 分词“独立结构”（如例2、3）、-ed分词“独立结构”（如例1、2）和无动词“独立结构”，即名（代）词+介词短语(如例4)、名（代）词+副词(如例6)或形容词（如例5）。
　　
　　六、形容词做状语的使用。例如：
　　
　　1．Disillusioned and disheartened， they are most likely to be collapsed under the weight of life.
　　2．Living in the warm nestle， safe and sound， they are utterly free from external hardships and ignorant of what the bare reality is like.
　　3．They swarm into the job market， curious and excited.
　　形容词常可单独或引起短语做状语，可用来表示原因（如例1）、方式（如例2、3）等。
　　形容词做状语位置比较灵活，可前可后或插在句中。
　　诚然，学生在真正使用英语表达（翻译、写作）不可能有过多的时间和精力去仔细揣磨每一字句，不可能锱铢必较。况且，语言表达的技巧又五花八门，其变化多样远非本文所能穷尽。但是，正所谓“台上一分钟，台下十年功”，若在平时的训练中能够有上述语言表达技巧意识和不断探索挖掘新的表达技巧意识，那必将大有裨益。长此以往，则能学会比较地道的英文表达。