There can be only one

Phrase repeated often on the Highlander movies and series. It means that two guys (or maybe women, in the series) are going to hack and slash at each other with swords until one beheads the other.

Here comes some translations in case you are a language-impaired immortal (from the Highlander FAQ):

French - Il ne peut y en avoir qu'un
Italian - Ne resterà soltanto uno
Spanish - Sólo puede quedar uno
Japanese - Hitori sonzai suru nomi
Korean - hanmyeong man isseul su isseoyo
German - Es Kann nur Einen geben
Afrikaans - Daar kan slegs een wees
Esperanto - Povas esti nur unu
Finnish - Vain Yksi Voi Jaada
Swedish - Den kan bara vara en or Det kan bara vara ett
Russian - Mozhet Bwit Syevo Adin
Polish - Tam Moze byc tylko jeden
Czech - Muzhe prezit jenom jeden
Latin - Potest esse nur unus
Hebrew - Suf davar echad levad
Yiddish - Tusm sof ken nor Zayn eyner aleyn
Tagalog - Puede be isa nalang
Klingon - rathlaHebj wa' neH

* I'm not sure of any (except Spanish), so /msg'me with corrections and additions. Thanks to Wonder Llama and his friend for the Czech correction and kudos to SwedishWhore for the um, Swedish one! Recent Korean addition thanks to Dystopian Autocrat. And our Italian Highlander is Vorbis.