This wiki is about idioms. Idioms are whole phrases extendended in meaning (though sometimes the word "idiom" is used for customary extensions of single words).
We should bear in mind that idioms usually belong to informal language, which is more common in spoken than in written English.
We can classify idioms according to a semantic field or topic of interest, or to a lexical area.
I will present some classifications of idioms, and please, feel free to include as many as you want.