A preposition is a word that tells you where or when something is in relation to something else. Examples of prepositions include words like 'after', 'before', 'on', 'under', 'inside' and 'outside'.

They cannot just stand by themselves. There is usually only one possibility of preposition which must be used after a particular noun. Occasionally alternatives are possible. But in either event ...

On the other hand, first-language speakers of German derive clarity about what or who is doing the biting, from the grammatical case: the dog (the subject) is in the nominative case and the boy (the ...