changing gears

Sruli is a full-fledged member of the why-what-why-where-why-who-why-two year olds, as Shev can attest to. We were out walking, and he was asking me what the man was doing. I did not see the man he was referring to, so he repeated himself again (and again) "what the man is doing?". "The man" looked up and told Sruli he was changing a gear in an engine, and Sruli asked if the gear was stinky. (Which led to the rest of the walk convo of why was he changing the gear...)