Prepositions are a class of words that indicate relationships between
nouns, pronouns and other words in a sentence. Most often they come before a
The good news is that they never change their form, regardless of the
case, gender etc. of the word they are referring to.
Prepositions are classified as simple or compound.
Simple prepositions are single word prepositions - across, after, at,
before, between, by, during, from, in, into, of, on, to, under, with and
without are all single word prepositions.