Englishfor English speakers
by
Preposition
—
near or next to.
The mailbox is by the bus stop.
—
at some time before (the given time).
Be back by ten o'clock!
—
if something is done by somebody, it is done through their action
The matter was decided by the chairman.
The boat was swamped by the water.
He was protected by his body armour.
—
if something is created by somebody, they are the creator, author, etc.
There are many well-known plays by William Shakespeare.
—
shows how someone does something
I avoided the guards by moving only when they weren't looking.
—
using the rules or logic of.
I sorted the items by category.
—
with a change of. In this case, by shows how much something has changed.
Our stock is up by ten percent.
—
shows how slowly, or how quickly, someone does something (used in the form "X by X" or "by Xs")
We went through the book page by page.
We crawled forward by inches.
—
If you multiply mathx/math by mathy/math, you multiply mathx/math × mathy/math.
Five multiplied by seven is 35.
—
If you divide mathx/math by mathy/math, you find how many mathy/maths are in mathx/math.
35 divided by seven is five.
a
Determinative
—
A is used when the following word could be any of a certain type.
Compare "A book I saw on the shelf" and "The book I gave you yesterday".
a
Noun
—
A is the first letter of the alphabet.
The letter "a" comes before "b".
—
In some schools, an A is a very high grade.
Ron got an A on his earth science test.
length
Noun
—
The length of an object is the distance between one end of that object and the other.
What is the length of the car?
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The length of a horse is used to show the distance between horses at the end of a race.
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Length is the distance down the pitch that the ball bounces on its way to the batsman.