Nema na čemu means “you’re welcome” and is the right reply when somebody thanks you.
The driver politely opens the back door for you, you thank him and he answers. Inside the car there is cigar smoke hanging in the air, and on the back seat sits your mum in a nightgown, telling you she has just arrived from the Czech Republic and brought her cow along – it is sitting in the boot going “moo”. Fog, mum, nightgown, Czech and the cow give you nema na čemu.
This is the first longer word image of the course. Expect two or three days before it feels right – and simply keep going during that time.