Introduction: A Preposition is a word placed before a noun or a noun-equivalent to show its relation to some other word in the sentence.
Generally, a preposition is used before a noun or pronoun. But, sometimes, a preposition is not used before a noun or pronoun.
Who was she talking to?
This is the bungalow he lives in.
This is the man whom I lent some money to.
(i) Prepositions can also govern other parts of speech used as Nouns.
From here, before now, for good, in short, about to go, etc.
(ii) Prepositions can also govern Phrases and Clauses.
I shall go to where you have come from
It depends on how you do your duty
I am ignorant of how to do it.
Phrase Prepositions or Prepositional Phrases are phrases used as prepositions, like - on account of, instead of, in spite of, by means of, owing to, by dint of, in accordance with, etc.
Classification of Prepositions
1. Preposition of Direction
Such as - to, to wards, for, along, against, across, up, down, into, etc.
2. Prepositions of Place / Position
Such as - at, in, on, above, below, over, under, between, among, amongst, amid, amidst, before, behind, etc.
3. Prepositions of Time
Such as - at, on, for, since, before, after, within, in till, by, during, from, etc.
4. Some Other Prepositions
Such as - about, off, of