Costermonger a secret language, a code which only other costermongers understood. In her book, "Shadows of the Workhouse", Jennifer Worth observed that "Costers... spoke to each other almost entirely in back slang; incomprensible to an outsider." Many costermongers also used "rhyming slang"; where any word can be substituted with another word that rhymes with it. Examples of rhyming slang include: "tin lids" or "dustpan lids" for "kids"; "jimmy grant" for "emigrant"; "apple and pears" for "stairs"; "rubbidy dub" for "pub" and "trouble and strife" for "wife". The selection of rhyming words often suggested a symbolic association. For example, a "sorrowful tale"
Apples and oranges niú bù xiāng jí), literally meaning "horses and cattles won't mate with each other", and later used to describe things that are totally unrelated and incomparable. A number of more exaggerated comparisons are sometimes made, in cases in which the speaker believes the two objects being compared are radically different. For example, "oranges with orangutans", "apples with dishwashers", and so on. In English, different fruits, such as pears, plums, or lemons are sometimes substituted for oranges in this context. Sometimes the two words sound similar, for example, Romanian "merele cu perele" (apples and pears) and the Hungarian "szezont a fazonnal"