Lesson Transcript

Hi, everybody. My name is Alisha. In this lesson, I'm going to talk about how to describe an object's dimensions. Dimensions means the size of an object, all of the different sizes of an object. I'm going to talk about a few key words that we need to describe these sizes, and I'm going to talk about how we make sentences that use this kind of information. So, let's get started.
First, I want to begin with this list of keywords for this lesson. So, I want everybody to be careful about the grammar of the sentences when they build these sentences. First, let's look at these words here. These words are all nouns. The words are "length," "width," "height," and
depth." Each of these nouns, when we use them to talk about the size of an object, explain some kind of question. By that, I mean, with "length," for example. "Length" tells us how long the object is. "Length," you can connect it with the word "long." Remember though, this is an adjective, how long is the item. "Length" is the noun form here.
Similarly, "width." "Width" tells us how wide is the object. So, "length" is how long. "Width" is how wide the object is. "Height" tells us how tall the object is. "How tall?" if that's our question, we're looking for the height of the object, how tall is the object. "My height is." That's what we would use to talk about it as a noun, not tall, which is the adjective form, but height. That's the noun form. Finally, "depth." We use "depth" to explain how deep an object is. We might use this more for things where we need to go under the ground, perhaps. In some cases, it's used for talking about buildings, like how far back something goes. We could also use this to talk about underwater measurements, or maybe like, as you'll see later, like a bathtub measurement, something that goes down. So, "depth" tells us how deep something is.
So, to review, "length" is how long something is. "Width" is how wide something is. "Height" is how tall something is. And, "depth" is how deep something is. So, when we are talking about these points, we use measurements. So, a measurement is the unit that we use to talk about these things. So, there are two systems in the world that are used. The U.S. is one of, I believe, only two countries that uses what's called the imperial system. In the imperial system, we use "inches," which we write in a short way, an abbreviation as "in," inches, and feet, which we abbreviate as "ft," feet; inches, "in." So, there are 12 inches in 1 foot. An inch is a small unit. A foot is a larger unit. There are 12 inches inside 1 foot. This is the imperial system.
Now, there are larger measurements in the imperial system, yes, but for today's lesson, I'm focusing on measurements of objects. I'm not going to talk about the larger measurements. Okay. But let's compare this to the metric system. Most of the world uses the metric system. In the United States, the imperial system is used. But most of the rest of the world uses the metric system. For today's lesson, I want to focus on these three key vocabulary words. They are "millimeters," which we abbreviate, we make short as "mm." We have "centimeters," which we abbreviate as "cm." And, finally, we have "meters," we abbreviate with "m."
For reference, inside 1 meter, there are 100 centimeters, and there are 1,000 millimeters. 1,000 millimeters, 100 centimeters inside a meter. If you're interested, you can break down this "centi" and "milli" to learn more about the histories of these words. But it's a little bonus point for those of you who are interested. Let's look at how we use this then to describe an object's dimensions to talk about the size of something with these words, too. I've drawn this object, a box for this lesson, and I have marked here 20, 40 and 60. So, I want to use these numbers to talk about the size of the object.
Let's take a look at a very basic way to describe these dimensions. This box is 20 centimeters, in this case, x 40 centimeters, x 60 centimeters. Very commonly in English writing and in writing I think maybe from other languages too, we see this x between our measurements. In English, we read this as "by." Naturally, I would say, "20 centimeters by 40 centimeters by 60 centimeters." And, if it's understood, if this unit of measurement is understood, we might say just 20 by 40 by 60, or 20 by 40 by 60 centimeters is also okay. We often don't need to say, "Centimeters, centimeters, centimeters" after each one because everything should be in the same unit of measurement. 20 by 40 by 60 is a very clear way to say that.
If you're using "inches," actually these are the same measurements, just in inches in the imperial system. You might see, for example, a dot in the number followed by a couple more numbers. These are the same measurements actually, just in the imperial system, in inches. To describe the dimensions of this box, I would say this box is 7.84 inches by 15.74 inches by 23.62 inches. Again, we're using "by" here. We read this, the dot as point. You'll also notice the number, or numbers, before the dot are read as regular. By that I mean, 7 and 15 and 23. Those are read as regular numbers.
The numbers after that are read individually, 7.84, not 7.84. We read it one at a time. Each number is read one at a time, 7.84 inches by 15.74 inches by 23.62 inches. When you need to read these small numbers after the decimal point, this is called a decimal point here, we just read it as point. Make sure to read these individually, not together. This is another small point about dimensions. Of course, you may see this in centimeters too, maybe 20.5 centimeters, for example. This is how we read these portions of the sentence, and also a point about reading the numbers, too.
So, how do we use the words "long" and "length" and so on? There are a couple of different ways to describe this. As I've said here, this is very common, using just the dimensions like this. We can do that. If you want to be very specific about your dimensions, you could say, for example, "This box is 20 centimeters long." That means the length of the box. In this case, maybe this is 20, for example. And also, maybe it's like the difference between "width" and "length" is sort of just up to the person who created the object, or maybe it's just for reference purposes. There's not like necessarily always a rule for which is width and which is length, but length tends to be longer than width.
For this example, probably 40, we would say, is the length and 20 is the width. But for this example sentence, this box is maybe 20 centimeters long. This is how I would use "long" in a sentence. However, if I want to use "length," the noun form I talked about earlier, "The length is 20 centimeters." Notice this sentence and this sentence are sharing the same information. "The length of the box." That's the information. But the grammar of the sentence changes. "This box is 20 centimeters long," adjective here. "The length is 20 centimeters," or, "The length of this box is 20 centimeters." Noun form and adjective form, length and long, they require slightly different sentence structures.
Let's look with wide and width then. Here, "This box is 40 centimeters wide." This is my adjective form. "The width is 40 centimeters." This is my noun form. We can do the same thing with tall and height. "This box is 60 centimeters tall," or, "The height is 60 centimeters." Again, "tall" is my adjective. "Height" is my noun. Depending on the word I use, I need to make sure my grammar, the structure of my sentence is correct. I cannot say, "The tall is 60 centimeters." That is incorrect because "tall" is an adjective. I must use a noun here. I also cannot use "height" in this pattern. "This box is 60 centimeters height" is incorrect because "height" is a noun. I have to use an adjective here. "It's 60 centimeters tall." This is correct. We use the same pattern when we're talking about people's height. "Her height is 160 centimeters," or, "She is 160 centimeters tall." Please keep this in mind when you're talking about the object's dimensions, the sizes of objects.
Finally, I mentioned the word "deep" or the word "depth," too. You might use this if you're talking about like your bathtub, for example. "My bathtub is 80 centimeters deep." Here, "deep," again this is the adjective form. To use "depth," we would make a pattern like this. "The depth of my bathtub is 80 centimeters," for example.
This is how we introduce sizes in English. Important points to takeaway are this "by" and this "point." This will help you sound more natural when you are reading dimensions for things. When you're taking a measurement of something, you can use this number, 20 centimeters. And then as you're taking the next measurement, it's very common to say "by," "20 centimeters by, 40 centimeters by, 60 centimeters," as you're measuring something. That's a very common way to express that.
I hope that this is helpful for you in terms of the measurements of objects, but if you have any questions or comments, or if there's something you would like to practice, if you want to make an example measurement, for example, in the comments section, please feel free to do that as well. Of course, if there's something else you want to know about this topic, please let us know in the comments, too. Thanks very much for watching this lesson and I will see you again soon. Bye-bye!

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