Idioms that all English-speaking cultures use.
Many English idioms are used predominantly in a specific region. People in New York know what a ‘blue plate special‘ is but people in Yorkshire don’t, and vice versa for ‘where there’s muck there’s brass‘.
However, many idioms are used by particular groups within society – the young, the old, sportspeople, hippies etc, etc. If you use an idiom that is common within one of these groups others might look blank.
Care also needs to be taken with slang. Your maiden aunt may not understand what a ‘nip slip’ is and she may not be best pleased to find out. Where an idiom is not in universal use the group or region where it would be appropriate is listed under ‘Where used?’.
Idioms that are listed as ‘Worldwide’ will be understood by almost all native English speakers you might be conversing with.
