Imagine someone saying to you “I am so bored of the novel I am reading.” Do you feel, with a kind of jolt, that the preposition “of” is out of place, and that it would be better and more idiomatic English to say “bored by” (or “bored with”) instead? Do you sometimes wonder which preposition to use—should it be “centered around” or “centered on”? Do we “protest about or (against) an injustice, or omit the preposition altogether? Where variants exist, are they equally acceptable, or are some preferable to others, some to be avoided.
What are prepositions? Easy. Prepositions are those diminutive and deceptively simple words, like “at,” “by” “for,” “in,” “of,” “on” and ”to,” which are entrusted with the humble task of connecting one part of sentence to another. They are the vital building blocks of the English language, and few sentences would be complete or even possible without them. Yet they are also the banana peels of modern speech and we constantly slip up on them. The unfortunate result is a rash of awkwardness, confusion and misunderstanding.