In a certain code language, 'first of all' is written as 'kan dan san', 'who is first' is written as 'zan kan ven', and 'this is pale' is written as 'ven gen len'. How will 'who' be written in that language?

zan

Given; In a certain code language, 'first of all' is written as 'kan dan san', 'who is first' is written as 'zan kan ven', and 'this is pale' is written as 'ven gen len'. 

So,

first  of  all  =  kan  dan  san

who  is  first  =  zan  kan  ven

this  is  pale  =  ven  gen len

Thus,

who is coded as zan.