Translation:How old is the student with whom you are expecting a child?
Could you also say something like "Kolik mu je, s ..." ? Are there any rules when i can / have to use "Kolik ..." and when i can / have to use "Jak starý ..."?
Thank you, but could I ask someone about his age with "Jak jsi/jste starý/á?" as well? Because I got taught to use "Kolik ti/vám je?"