How are u? - aap kaisey hain ?(with repect) and with frnds and younger than you - tum kaisey ho ? how = kaisey. You = tum or Aap. " are " can't be defined as a single word in hindi. How old are u ???(explain what is old) Aap ka umar kya hai ? or Aap kitney saal ke ho ? old means - purana but not used in sentence while asking this question. What´s your name ? (explain what is your , is and name) aapka naam kya hai ? your = aapka or tumhara & is = hai & name = naam. Where are u from??? ( explain what is where and from) aap/tum kahan se ho ? where = kahan & from = se.

Jimmy ne bahut sahi jawab diye hai. Mr. Jimmy has answered it correctly. Nothing much to comment on.

aap kaise ho? aapki umar kya hai? aapka naam kya hai? aap kaha se ho?

tum kese ho how mean kete you mean tum

Mr.Jimmy is exactly right........