If it's too long people might use In Polish: Olek In Finnish: Santeri In English: Zander In English: Alex In English: Lex In Dutch: Xander
For the opposite sex use: In Spanish: Alejandra (F) In Russian, Polish, Serbian and in Bulgarian: Aleksandra (F) In Italian: Alessandra (F) In German, Scandinavian, Dutch, English, Greek, Portuguese, Romanian, Czech, Hungarian and in Ancient Greek: Alexandra (F) In English: Alexandrea (F) In English: Alexandria (F)
See also In Russian: Sasha (B) In Esperanto: Alechjo (M) In English: Alec (M)