"They go between Dublin and Cork."
Translation:Téann siad idir Baile Átha Cliath agus Corcaigh.
Idir can mean "both" or "between"
"both young and old were present" - bhí idir óg agus aosta i láthair
"it was both funny and sad" - bhí idir ghreann agus bhrón ag baint leis
"the work is split between two offices" - tá an obair roinnte idir dhá oifig
"a crash between a bus and a lorry" - tuairt idir bus agus leoraí