A preposition describes a relationship between other words in a sentence. In itself, a word like "in" or "after" is rather meaningless and hard to define in mere words. For instance, when you do try to define a preposition like "in" or "between" or "on," you invariably use your hands to show how something is situated in relationship to something else. Prepositions are nearly always combined with other words in structures called prepositional phrases. Prepositional phrases can be made up of a million different words, but they tend to be built the same: a preposition followed by a determiner and an adjective or two, followed by a pronoun or noun (called the object of the preposition). This whole phrase, in turn, takes on a modifying role, acting as an adjective or an adverb, locating something in time and space, modifying a noun, or telling when or where or under what conditions something happened.
Prepositions Of Time : at, on, and in
We use at to designate specific times.
- The train is due at 12:15 p.m.
- My brother is coming on Monday.
- We're having a party on the Fourth of July.
We use in for nonspecific times during a day, a month, a reason, or a year.
- She like to jog in the morning.
- It's too cold in winter to run outside.
Prepositions of Place : at, on, and in.
We use at for specific address.
- Grammar English live at 55 Boretz Road in Durham.
We use on to designate name of streets, avenues, etc.
- Her house is on Boretz Road.
And we use in for the names of land-areas (towns, countries, states,countries, and continents).
- She live in Durham.
- Durham is in Windham Country.
- Windham Country is in Connecticut.
Common Combination and Preposition.
Most phrasal verb is composed of two words: verb + particle. But some are made up of three words, namely: particle + verb + preposition, which is known as phrasal-prepositional verb. So phrasal-prepositional multi-word verb is a verb which consists of a verb, particle and preposition.
Between particle (adverb that looks like a preposition) and phrasal preposition on-prepositional verb inseparable (inseparated) and the object is always to follow the multi-word verb is due to end in the form of a preposition (preposition always has an object). Because it is always followed by an object, all phrasal-prepositional verb is transitive.
http://grammar.ccc.commnet.edu/grammar/prepositions.htm
http://dictionary.cambridge.org/grammar/british-grammar/about-nouns/nouns-and-prepositions
