Uh Ah?

joshua: ...kah li you...
mahmmyboy: ? (could not comprehend...)

Finally managed to decipher one day. We were at Kiddy Palace and joshua was admiring his favourite range of trains (Thomas, what else...). He was pointing at Dennis (name of a train) and he mentioned those words again. At that moment then i realised what he was saying. He was actually telling me (in mandarin) jia li you...