VOA · Everyday Grammar
Advanced · C1learner speed7:192024-05-29public domain
Everyday Grammar digs into one grammar topic per episode — verb tenses, prepositions, sentence patterns — with plenty of spoken examples. Because you are listening to language about language, it doubles as grammar review while you train your ears.
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01What do news stories about space travel, technology, or energy production have in common?
02Well, one way to answer this question is to look at special prefixes that are often used with measurements in science and industry.
03These prefixes are especially important to people studying in the STEM fields of science, technology, engineering, and math.
04Let's start with some important terms and ideas.
05Prefixes are additions to the beginnings of words.
06When we add a prefix to a word, it changes the meaning of the existing word, and the result is a new word.
07Let's take an example to clarify the point.
08We have the prefix un, meaning not.
09Then we have the full word happy.
10When we add the prefix un to the beginning of the word happy, we get the word unhappy.
11There are many kinds of prefixes.
12For today's lesson, we will pay attention to one kind of prefix.
13Prefixes related to large amounts.
14The National Institute of Standards and Technology, or NIST, is a U.S.
15government agency that works on measurement science.
16NIST has a public list of prefixes used for amounts or quantities and their meanings.
17The list is long.
18But there are only a few of these prefixes that are important for everyday uses in the sciences and industry.
19The prefixes that mean one thousand, one million, one billion, and one trillion are useful to know for most kinds of science, energy, and technology stories.
20Here is how NIST defines these prefixes.
21Kilo means thousand.
22Mega means million.
23Giga means billion.
24Terra means trillion.
25In science and industry, we often use large number prefixes to express measurements of distance, energy, or weight.
26An example of a distance measurement is a meter.
27An example of a power measurement is a watt.
28Let's take an example that everyone knows.
29One kilometer.
30We have the prefix kilo, meaning one thousand, and the unit of distance, a meter.
31Let's listen to how Brian Lynn uses the term kilometer in a recent science story on our website.
32NASA estimates the moon sits an average of about 382,500 kilometers from Earth.
33The exact distance changes because of the moon's orbit around Earth.
34The average distance from Earth to Mars is 225 million kilometers.
35Our example shows an important point about agreement.
36Note that in our example, we make the measurement of distance plural.
37We add an S to the end of kilometer, and so we get the term kilometers.
38So, we say one kilometer, two kilometers, and three hundred thousand kilometers.
39The idea is that the prefix changes the meaning of the word, but the word must still agree in terms of being singular or plural.
40So, do not forget about the plural markers we use at the ends of words.
41We can carry this same idea to an energy story.
42A watt is a unit of power.
43When we use prefixes to change the meaning, we arrive at a term such as a megawatt, meaning a million watts, or a gigawatt, meaning a billion watts.
44Let's listen to part of a recent report about wind energy development in 2023.
45The Global Wind Report, published recently by the Global Wind Energy Council, or GWEC, a trade group, said the world developed 117 gigawatts of new wind power capacity, a 50% increase from 2022.
46Note that in our example, the power capacity measurement is expressed in gigawatts.
47Once again, we add the S ending to gigawatt because it is plural.
48One hundred seventeen gigawatts.
49Let's take some time to work with these ideas.
50Imagine you want to describe the amount of data that a hard drive can hold.
51Use the prefix tera and the unit of computer information, a byte, to describe the storage capacity of the hard drive.
52Pause the audio to consider your answer.
53Here is one possible answer.
54This hard drive has one terabyte of data storage capacity.
55Here is another possible answer.
56This hard drive has two terabytes of data storage capacity.
57We will end this everyday grammar with a call to action.
58Write us a short description of something related to science, energy, or technology.
59Be sure to use prefixes such as kilo, mega, giga, or terra.
60Try to connect your description to something related to your country or your life.
61You can write us your answers in an email to learningenglish at voanews.com.
62In a future everyday grammar, we will give feedback on some of the messages we receive.
63I'm John Russell.
64I'm John Russell.
65I'm John Russell.
66I'm John Russell.
// transcribed with Whisper AI — reading it is easy; catching it by ear is the skill
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