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.
breath
Noun
—
Your breath is the air that you move into and out of your lungs.
After running for just a minute, his breath was coming quickly.
—
A breath is the air that you move into and out of your lungs one time.
Take a big breath and put your face in the water.