I'm struggling to understand why 'kore' is subject here. Can anyone explain why in words that a Brit of small brain can comprehend? It appears that the concept of subject is not the same as in English, but maybe I'm just missing the point. ;-)
Japanese, as you know, is (S)OV, wherein that structure the subject (S) is optional. The reason subjects are optional may have to do with the fact that stating something too directly is just not done in Japanese. The topic marker 'wa' is often used to introduce a new subject. Its meaning is something along the lines of "As for...".
:kore wa nan to iimasu ka
: this-as for-how-say-it?
: As for this (thing here that I am pointing at) how do you say it?
: What is this called? (Question, subject = 'this')
: This is called____. (Answer, subject = 'this')
Another way of stating it is this,
(pointing at something) "Nan to iimasu ka." You don't really need the subject "kore wa".
Spoken Japanese: Kore wa, nan te iu no? (to becomes 'te' before high front vowels, especially 'i'. Also, 'iu', to say, is pronounced 'you')
English: What's this (thing) called?
Fire away with the questions. I love Japanese syntax! You can email me, too.