一、动词不定式
在《计算机英语》中，动词不定式大量用来作状语或定语。
1．动词不定式在句首或句末常常用来表示目的，可以译成“为了……”“以便……”，可见这个时候起状语的作用。例如：
（1）We use good tools to do a good job.
（2）To do a good job， we use good tools.
（3）We must do every thing we can to help them.
由于英语中常用被动语态，所以上面的例（1）可以表示为：
（4）Good tools are used to do a good job.
注意例子中的不定式部分，这类句型在《计算机英语》中大量的出现。类似的句型还有：
（5）A circuit of the demultiplexer is arranged to detect the synchronization word， and thereby it knows that the next group of 8-digits corresponds to channel 1.
（6）Furthermore， we shall prove that a minimum theoretical sampling frequency of order 6.8 kilohertz is required to convey a voice channel occupying therage 300 Hz to 3.4 kHz.
（7）As each incoming bit is sampled， it is used to construct a new character.
（8）Timing signals from the interface assembly at the transmitter are appliedto the data modem to synchronize the computer and the data set.
（9）The switching centers are linked together by trunks. These trunks are designed to carry multiple voice-frequency circuits using either FDM orsynchronous TDM.
（10）The 10 regional centers are meshed together to provide full connectivity.
2．动词不定式在名词之后常用来表示定语，译成“……的……”。例如：
（1）She usually has a lot of meetings to attend in the evenings.
（2）I want to get something to read during the vacation.
（3）She was the first person to think of the idea.
（4）This will be a good opportunity to exchange experience.
（5）The operator of a local telephone switchboard had an option to transmit an optical of acoustical signal for the searched person over a wired network.
（6）Why 800 MHz？ The FCC’s decision to choose 800 MHz was made because of server spectrum limitations at lower frequency bands.
（7）Any communication systems which can provide customers with means to communicate from any place， at any time and at any distance give social andeconomic advantages.
二、动名词
动名词的作用相当于名词，它在句子中可作主语、宾语或介词宾语。例如：
（1）（Reading is a good habit.
动名词在句子中作主语。
（2）I enjoy working with you.
动名词在句子中作宾语。
（3）I am interested in reading.
动名词在句子中作介词宾语。
动名词的作用虽然相当于名词，但它仍然具有一些动词的特征。例如，它可以有自己的宾语和状语。如以下例句：
（4）I am interested in carefully reading books.
（5）He insisted on doing it in his own way.
（6）What would you suggest for overcoming the difficulties？
在《计算机英语》中，动名词的应用相当普遍，请看下面的例子：
（7）Digital transmission provides a powerful method for overcoming noisyenvironments.
（8）Consequently there is an inherent advantage for overcoming noisy environments by choosing digital transmission.
（9）The telephone contains a transmitter and receiver for converting back and forth between analog voice and analog electrical signals.
三、现在分词
1．现在分词一般作形容词用，可修饰动作的发出者，有主动的意义。可译成“……的……”，此时多作定语。例如：
（1）The smiling girl is Wangling.
（2）This is an amusing story.
在更多情况下，我们可以用现在分词短语作定语，在意思上和一个定语从句差不多。例如：
（3）The girl standing by the window talked to her friend.
（4）There are lots of boys on the sports ground playing football.
（5）They built a highway leading into the mountains.
在《计算机英语》中，现在分词的英语很普遍，有如下例子：
（6）Thus the output to the codec may be seen as a sequence of 8 pulses relating to channel 1， then channel 2， and so on.
（7）In addition to defining standards covering the NNI， CCITT also embarked on a series of standards governing the operator of synchronous multiplexers and SDH network management.
（8）The unquestionable success of the first generation of paging systems using wired networks with signaling devices was following in the early 1950s by technological progress in the miniaturization of electronic circuitry.
2．现在分词还可以作状语，用来表示方式、目的、条件、结果和背景等等；有时表示主语在作一个动作的同时还进行的另一个动作，此时称之为伴随状态。例如：
（1）Every evening they sit in sofa watching TV.
现在分词起伴随作用。
（2）I read the English book， using my dictionary.
现在分词表示条件或背景。
还可以列出一些例子：
（3）I ran out of the house shouting.
（4）Not knowing her address， we couldn’t get in touch with her.
（5）She got to know them while attending a conference in Beijing.
（6）At the receiving end of an asynchronous serial data link， the receiver continually monitors the line looking for a start bit.
（7）Generally， this link has lower capacity than the total number of PBX subscribers， reflecting the fact that， at any given time， only a fraction of the subscribers will be engaged in external calls.
四、过去分词
1．过去分词（短语）一般作形容词用，可以修饰动作的对象，有被动的意义。可译成“被……的……”或“由……的……”，此时多作定语。例如：
（1）The trees planted by me have grown up.
（2）What’s the language spoken in this area？
（3）Suddenly there appeared a young woman dressed in green.
（4）For example， the signal received from a satellite， located in far outer space， is very weak and is at a level only slightly above that of the noise.
（5）Once the start bit has been detected， the receiver waits until the end of the start bit and then samples the next N bit at their centers， using a clock generated locally by the receiver.
（6）The ideal mobile telephone system would operate within a limited assigned frequency band and would serve an almost unlimited number of users in unlimited areas.
（7）In addition to the five classes of switching centers listed above， the network is augmented with additional switching nodes called tandem switches.
（8）This is actually a collection of national networks interconnected to form a international service.
五、状语从句
用作状语的从句叫做状语从句，根据其用途，状语从句可以分为：
1．时间状语从句，其关联词除了常见的after， before， once， since， till 等外，一些表示时间的副词和短语，如：directly， immediately， the minute， the second， by the time 等，也可以引导时间状语从句。
By the time these various radio waves reach the earth they are naturally veryweak.
在科技英语中，时间状语从句有时表示条件。例如：
Immediately/Instantly the button is pressed， the power supplies.
一按电钮，电就来了
2．地点状语从句，其关联词有：where， wherever， anywhere， everywhere等。例如：
In general， where there is little water， you don’t find green field.
3．原因状语从句，其常见的关联词有：because， as， since等。
Theory in valuable in that it can provide a direction for practice.
另外，有些表示原因的短语，如：seeing that， in as much as 等也可引导原因状语从句。
