Before dealing in detail with the special uses of some Prepositions, let us understand what are the primary function of a Preposition in a sentence structure?
Prepositions are words that are used to link the Noun or Pronuon to another part of the sentence.
Examples: On, It, At
The primary function of a Preposition is to indicate time, direction or location of an object.
Prepositions invariably must contain a Subject and verb before it and follow it up with another Noun or Pronoun, not a verb.
· He put the eggs in the wrong basket.
· She is going to her hostel in December.
· I’ll meet you at sharp 6.30 p.m.
Special Use of In and At
Both “in”/ “at” can be used for cities, towns and villages.
“In” is used for a general location whereas “At” points out to a specific location / point.
· My sister lives in Delhi.
· Our plane stopped at Delhi on our way to Chandigarh.
“At” is used to talk about group activities or shops or workplaces, specifically
· I bumped into him at a party.
· I saw him at the mall.
“In” is used with the names of streets and “at” for the specific House Number.
· I live in Dumdum area.
· I live at 85, R.N Guha Road.
“In” is used before a Noun to denote a certain period of time where it is used in sense of “within”
· I shall be back in a an hour.
“By” means of something or someone and is mostly made use of in Passive sentences.
· Do you usually travel by train?
· He was beaten to a pulp by me.
· The letter was written to him by Raghav.
With means accompanied by someone or something.
· I will always be with you.
· I have brought a pie with me.
· H is playing with his toys.
· It is an add on with the original product.
“On” is also used to denote on top of a surface.
· The eggs are kept on the table.
· I have to climb on the rooftop to reach there.
“Till” and “Until”
Both are used to denote time
· We waited till 2 p.m. for the show to start.
· They slogged until the project got completed.
It is used before a Noun / phrase to denote some point of time and is preceded by the verb in the perfect tense.
· I have not seen him since last summer.
· It has been three years since we parted.
“Before” / “After”
They are used to denote the time period of an event or an action specifically in relation to another thing.
· We cannot leave the party before 1 p.m.
· We left after the show ended at midnight.
(Other prepositions of time are throughout, during, around, about)
Denotes movement from one place to another.
· We moved across six continents in the last 10 years.
· He swam across the turbulent river to fetch help.
Denotes moving inside something and out from the other end.
· The thread goes through the needle.
· I can look through the glass.