Prepositions and postpositions, together called adpositions (or broadly, in English, simply prepositions), are a part of speech (class of words) that express spatial or temporal relations (in, under, towards, before) or mark various semantic roles (of, for).
A preposition or postposition typically combines with a noun or pronoun, or more generally a noun phrase, this being called its complement, or sometimes object. A preposition comes before its complement; a postposition comes after its complement. English generally has prepositions rather than postpositions – words such as in, under and of precede their objects, such as in England, under the table, of Jane – although there are a few exceptions including “ago” and “notwithstanding”, as in “three days ago” and “financial limitations notwithstanding”. Some languages that use a different word order, have postpositions instead, or have both types. The phrase formed by a preposition or postposition together with its complement is called a prepositional phrase (or postpositional phrase, adpositional phrase, etc.) – such phrases usually play an adverbial role in a sentence.
A less common type of adposition is the circumposition, which consists of two parts that appear on each side of the complement. Other terms sometimes used for particular types of adposition include ambiposition, inposition and interposition. Some linguists use the word preposition in place of adposition regardless of the applicable word order.
Near or next to.
“The mailbox is by the bus stop.”
At some time before (the given time), or before the end of a given time interval.
“Be back by ten o’clock!”
“We will send it by the first week of July.”
Indicates the actor in a clause with its verb in the passive voice: Through the action or presence of.
“The matter was decided by the chairman.”
“The boat was swamped by the water.”
“He was protected by his body armour.”
Indicates the creator of a work: Existing through the authorship etc. of.
“There are many well-known plays by William Shakespeare”
Indicates the cause of a condition or event: Through the action of, caused by, responsibility for; by dint of.
Indicates a means: Involving/using the means of.
“I avoided the guards by moving only when they weren’t looking.”
Indicates a source of light used as illumination.
“The electricity was cut off, so we had to read by candlelight.”
Indicates an authority, rule, or permission followed.
“I sorted the items by category.”
“By the power vested in me, I now pronounce you man and wife.”
Indicates the amount of some progression: With a change of.
“Our stock is up by ten percent.”
In the formulae X by X and by Xs, indicates a steady progression, one X after another.
“We went through the book page by page.”
“We crawled forward by inches.”
Indicates a referenced source: According to.
“He cheated by his own admission.”
Indicates an oath: With the authority of.
“By Jove! I think she’s got it!”
“By all that is holy, I’ll put an end to this.”
Used to separate dimensions when describing the size of something.
“It is easy to invert a 2-by-2 matrix.”
“The room was about 4 foot by 6 foot.”
“The bricks used to build the wall measured 10 by 20 by 30 cm.”
Designates a horse’s male parent (sire); cf. out of.
“She’s a lovely little filly, by Big Lad, out of Damsel in Distress.”
Along a path which runs by the speaker.
“I watched as it passed by.”
In the vicinity, near.
“There was a shepherd close by.”
“The shop is hard by the High Street.”
To or at a place, as a residence or place of business.
“I’ll stop by on my way home from work.”
“We’re right near the lifeguard station. Come by before you leave.”
“The women spent much time after harvest putting jams by for winter and spring.”
Out of the way, subsidiary.
alternative spelling of bye
From one side of an opening to the other.
“I went through the window.”
Entering, then later leaving.
“I drove through the town at top speed without looking left or right.”
Surrounded by (while moving).
“We slogged through the mud for hours before turning back and giving up.”
By means of.
“This team believes in winning through intimidation.”
To (or up to) and including, with all intermediate values.
“from 1945 through 1991;”
“the numbers 1 through 9;”
“your membership is active through March 15, 2013”
Passing from one side of something to the other.
“Interstate highways form a nationwide system of through roads.”
“They were through with laying the subroof by noon.”
Valueless; without a future.
“After being implicated in the scandal, he was through as an executive in financial services.”
No longer interested.
“She was through with him.”
Proceeding from origin to destination without delay due to change of equipment.
“The through flight through Memphis was the fastest.”
In possession of the ball beyond the last line of defence but not necessarily the goalkeeper; through on goal.
From one side to the other by way of the interior.
“The arrow went straight through.”
From one end to the other.
“Others slept; he worked straight through.”
“She read the letter through.”
To the end.
“He said he would see it through.”
“Leave the yarn in the dye overnight so the color soaks through.”
Out into the open.
“The American army broke through at St. Lo.”
A large slab of stone laid in a dry-stone wall from one side to the other; a perpend.
A coffin, sarcophagus or tomb of stone; a large slab of stone laid on a tomb.
identifying the agent performing an action.
after a passive verb
“damage caused by fire”
“the door was opened by my cousin Annie”
after a noun denoting an action
“years of hard fund-raising work by local people”
“a clear decision by the electorate”
identifying the author of a text, idea, or work of art
“a book by Ernest Hemingway”
indicating the means of achieving something
“they substantiate their opinions by the use of precise textual reference”
“they plan to provide further working capital by means of borrowing”
“malaria can be controlled by attacking the parasite”
indicating a term to which an interpretation is to be assigned
“what is meant by ‘fair’?”
indicating a name according to which a person is known
“she mostly calls me by my last name”
indicating the means of transport selected for a journey
“the cost of travelling by bus”
“I travelled to Folkestone by rail”
indicating the other parent of someone’s child or children
“Richard is his son by his third wife”
indicating the sire of a pedigree animal, especially a horse
“a black filly by Goldfuerst”
(followed by a noun without a determiner) in various phrases indicating how something happens
“I heard by chance that she has married again”
“she ate by candlelight”
“Anderson, by contrast, rejects this view”
indicating the amount or size of a margin
“the raising of VAT by 2.5%”
“the shot missed her by miles”
indicating a quantity or amount
“billing is by the minute”
“the drunken yobbos who turned up by the cartload”
in phrases indicating something happening repeatedly or progressively, typically with repetition of a unit of time
“colours changing minute by minute”
“the risk becomes worse by the day”
identifying a parameter
“a breakdown of employment figures by age and occupation”
expressing multiplication, especially in dimensions
“she multiplied it by 89”
“a map measuring 400 by 600 mm”
indicating a deadline or the end of a particular time period
“by now Kelly needed extensive physiotherapy”
“I’ve got to do this report by Monday”
indicating location of a physical object beside a place or object
“remains were discovered by the roadside”
“the pram was by the dresser”
past and beyond
“I drove by our house”
indicating the period in which something happens
“this animal always hunts by night”
concerning; according to
“she had done her duty by him”
“anything you do is all right by me”
used in mild oaths
“it was the least he could do, by God”
“I swear by Almighty God”
so as to go past
“a car flashed by on the other side of the road”
“he let only a moment go by”
variant spelling of bye