How would one say "who´ s that?" in Turkish

Thank you

 kim ne?

 "Bu kim?" actually

 yes, indeed

Surely that´s ´Who´s this?´  -  ´Who´s that?´ would be ´O kim?´ 

 Surely that´s "Who´s it/he/she" - "Who´s that" would be "Þu kim?"

Can´t argue with a native speaker can I?   But if ´Ãžu kým´ = ´Who´s that?´ (and I know both ´Ã¾u´ and ´o´ can be used for ´that´ then surely ´bu kim´ must be ´who is this?´ because ´who is he/she/it?´ would be ´o kim?´.

Doðru mu?.  And in English we would equally say ´Who is he/she/that?´ or ´Who is he/she/this?´ 

"bu=this" is used for the nearest thing or person in Turkish.

 You are right. Im just playing In Turkish, although "this=bu" and "that=þu (and ´o´ like you said)" native speakers usually don´t differentiate while making tranlations (especially simultaneous translations).  I mean;

"Who´s that girl" - Þu kýz kim?  - grammatical

"Who´s this girl" - Bu kýz kim? - grammatical

"Who´s that girl" - Bu kýz kim? - not grammatical but more practical

"Who´s this girl" - Þu kýz kim? - not grammatical, not practical, not wrong

All of them are true.

Agree. Just to add my 2 pennorth:

Bu kim?: I would say this when pointing at a person in a picture.

Kim o?: I would use this when answering the doorbell.